Juan Pablo Montoya believes that Andreas Seidl is McLaren's 'X Factor', and has played a critical role in the team's resurgence.
Montoya, who drove for McLaren's F1 team in 2005 and 2006 and recently rejoined McLaren in IndyCar for the Indy 500, believes the German engineer has revolutionised the team's way of thinking since he joined in mid 2019.
"Since joining the team he has revolutionised the mentality of all team members, radically changing their way of approaching work", Montoya told Motorsport TV.
Montoya worked with Seidl at Williams between 2001 and 2004, when BMW were the works engine supplier to the British team, and the Colombian praised the engineer for what he views as a 'rare gift'.
"[He] always works great, has personality and the rare gift of always sensing what the team really needs," Montoya said.
With McLaren in the running to finish third in this year's championship fight, Montoya believes next year's regulation changes are a huge window of opportunity for the Woking team to finally return to the top step of the podium for the first time in a decade.
“The real big goal is 2022," Montoya said.
"The battles are very open, everything will depend on who will be able to build the winning machine."