After the 2020 grid had remained pretty stagnant from the previous season, 2021 saw one of the biggest range of driver line-up changes in recent years; in fact, only three out of the 10 F1 teams kept the same driver pairing for this year. There were some big names involved in this too, with the likes of Ferrari, Red Bull and McLaren all recruiting new teammates for their remaining driver.
For some, the move proved to be a difficult one to adapt to at the beginning. Sebastian Vettel endured a tough start to his Aston Martin career after making the switch from Ferrari, whilst Carlos Sainz - the man who replaced him at the Scuderia - seemed to struggle to match Charles Leclerc in the early races of the season. Since then, though, both drivers have showed an improvement in form, and have at times been outperforming their stablemates in recent Grand Prix weekends.
There are others who appear to be continuing to struggle, though. The following drivers will be hoping that their fortunes reverse pretty soon...
When Sergio Perez was given the 2021 seat at Red Bull, it felt like a long-awaited opportunity; the Mexican has often impressed with his performances in midfield cars, not least when he earned a surprise victory at the 2020 Sakhir Grand Prix with the then-Racing Point team. It was hoped that being given a drive with a leading outfit could finally offer Perez the chance to fight much more regularly for wins.
So far, though, this hasn't been the case. Perez has showed flashes of his usual skill, in instances such as a front-row qualifying position at the Emilia Romagna Grand Prix and how he utilised his tyre management abilities at the Portuguese Grand Prix to stay out for 52 laps. But as of yet, the one-time race winner has not come close to matching teammate Max Verstappen, and this is perhaps concerning the team when it comes to the Constructors' Championship battle.
Verstappen seemed to hint at this when he lost out to Lewis Hamilton at the Spanish Grand Prix thanks to Mercedes' strategy call, something that Red Bull could not have replicated with Perez back in fifth place.
"I am always alone in the fight, so they can easily make another stop because there is a gap behind them," the Dutchman told Ziggo Sport.
Red Bull advisor Dr Helmut Marko has also voiced his displeasure over Perez not being able to play the back-up role in a similar way to Mercedes' Valtteri Bottas.
"He's been too weak in qualifying so far," Marko recently told Sport Bild. "If he were on par with Bottas, I don't think Mercedes would have played a two-stop strategy in Barcelona. That's our biggest handicap at the moment."
Given Red Bull's history of making changes to their driver line-up - see Pierre Gasly and Alex Albon - Perez will definitely be hoping to make Marko happier with his performances very soon.
Following the end of his two-year spell at Renault, Daniel Ricciardo seemed full of enthusiasm about joining McLaren. Given that the Woking-based squad have been on the up in recent years, the Australian was arguably joining them at the best possible time. It offered an opportunity for the former race winner to bring his experience to the team and help them to move even further up the grid.
In the first few races of the 2021 season, though, Ricciardo has been outperformed by his new teammate Lando Norris. This has perhaps come as a surprise to some, given that Ricciardo is the more experienced driver in terms of length of time in Formula 1. But Norris possesses the advantage of being far more familiar with McLaren; the Briton first joined the squad back in 2017 as a junior driver before making the step-up to a full-time race seat in 2019, and since then has gone from strength to strength.
With this long-standing relationship, Norris understandably seems at home at McLaren, and this was cemented by the fact that the 21-year-old recently signed a new deal to remain with the outfit beyond this year.
All of this appears to have added to Norris' confidence, which could perhaps in turn be contributing to Ricciardo struggling more. The Australian was lapped by Norris during the Monaco Grand Prix - one of his favourite tracks on the calendar and one he has previously enjoyed victory at - during what was a challenging weekend for him. Understandably, Ricciardo admitted afterwards that this was not fun.
"I think being lapped by anyone in general doesn't feel that good," Ricciardo told select members of the media including RacingNews365.com. "I was kindalike hands up in the air, 'like what do you do?', this is the weekend that it is.
"I was kind of already so far removed from thinking that the result was gonna be good. To be honest, my race was already painful, I think the weekend was was one to forget."
Sadly this has not been Ricciardo's only tough moment of the season. Things are perhaps taking longer to click than expected, and the Australian has admitted that he is still trying to become comfortable with the car. But given that there seemed to be progress at the recent Spanish Grand Prix, there are signs that things will get better for Ricciardo and McLaren.
A man who finds himself in a similar situation to Ricciardo is Fernando Alonso. Like the Australian, Alonso has so far been outshone by his younger and less experienced teammate. But also like the set-up at McLaren, Esteban Ocon might have fewer races behind him but is ultimately more familiar with the Alpine outfit, having raced for the team in 2020.
Alonso has not had the start to 2021 that many expected. Despite being away from F1 for two years, the Spaniard's reputation as one of the best drivers of recent years meant that there were high hopes for his return. And things got off to a fairly promising beginning, when he managed to get the struggling Alpine into Q3 for the season-opening race in Bahrain.
The promise of a points finish in the Grand Prix was taken from Alonso when he was forced to retire the car due to a sandwich wrapper becoming lodged in one of the brake ducts. But in the races that followed, Alonso struggled to match this performance. Like Ricciardo, the Spaniard seemed to be finding it difficult to become comfortable with the car. This has probably been even more of a challenge for Alonso, given his absence from the sport for 24 months.
Alonso has been honest about the fact that he has found his return to F1 more challenging than he had anticipated.
"It’s not that I took it for granted that the results were coming automatically," the double World Champion told Racer.com. "I knew that the preparation was needed and the hours in the simulator and the 2018 tests in Bahrain and Abu Dhabi were needed, so I anticipated this, but I’m still struggling to maximise the potential of the car."
Alonso has also made it clear that he is viewing this season as a transition year before the 2022 rule changes come into effect, seemingly taking the pressure off for 2021. But it is hard to believe that the Spaniard would be happy to continue to be outscored by Ocon throughout the rest of the season.
Not all of the new teammates facing struggles in 2021 are drivers who have switched between F1 teams. For Yuki Tsunoda, his rookie season in Formula 1 - after making the step up from Formula 2 - has not been the easiest one.
There was much excitement over Tsunoda when he put in an impressive performance at the first race of the year in Bahrain, securing points with a ninth-place finish. Yet things seemed to start to unravel from then on, from a crash in qualifying for the Emilia Romagna Grand Prix to his particularly difficult weekend at the Spanish Grand Prix.
One of the issues here is that there have been mistakes both on and off the track. In Barcelona, Tsunoda made comments following a tough qualifying session where he appeared to suggest that AlphaTauri were not giving him the same equipment as teammate Pierre Gasly. The Japanese driver soon apologised for the remarks, but his weekend did not improve when he was forced to retire from the Grand Prix due to a mechanical failure.
Tsunoda received criticism for his outburst from several F1 pundits, though Gasly for one seemed to understand that the youngster is still learning.
"Yuki obviously had a tough qualifying yesterday, and he is quite emotional," the Frenchman told RacingNews365.com and other select media.
"So I think it’s a bit of emotional control. But he’s also young and I believe he will learn and improve on this side of things."
Tsunoda might be young but, given the unforgiving nature of life in the Red Bull family, he is already under pressure to improve. Dr Helmut Marko has spoken of the decision for Tsunoda to move from the UK to Italy - where AlphaTauri are based - so that he can be under the supervision of team boss Franz Tost. Marko has not been entirely pleased with Tsunoda so far.
"The development has certainly not been positive," Marko told Motorsport-Total.com. "His self-confidence took a hit after the multiple incidents, and that's why we decided to bring him to Italy from England.
"It's not only so we can control him better, but also to instil in him a stronger sense of security. His potential is still there."
So Red Bull are practising patience. But with Gasly showing his experience over Tsunoda both in their on and off track demeanours, the rookie will need to show improvement soon.