Christian Horner was left to rue a "brutal" end to the season-opening Bahrain Grand Prix for his Red Bull team, with Max Verstappen and Sergio Perez both hit by terminal technical issues.
Verstappen was running in P2 in the closing stages, having earlier challenged Ferrari's Charles Leclerc for the lead, when he reported power steering and battery problems at the wheel of his RB18.
Following a late Safety Car, Verstappen's issues worsened and he was forced to pull into the pits to retire, with teammate Perez - promoted to third - spinning out on the final lap and radioing in an engine fault.
Horner looks back on "brutal" end to Red Bull's race
Horner could not hide his disappointment as he stepped off the Red Bull pit wall to do his usual post-race media rounds.
While the exact issues suffered by the two drivers could not be confirmed, Horner suggested that they are related to the fuel system.
"It's a brutal finish to that race for us," Horner told Sky Sports.
"What looked like a decent haul of points obviously evaporated in the last couple of laps there.
"We don't know exactly what it is yet, whether it's a lift pump, whether it's a collector, or something along those lines, but we've gotta get into it and understand exactly what's caused it."
"Similar failure" for Verstappen and Perez
Horner suspects, but cannot yet confirm, that Verstappen and Perez suffered similar failures at the end of the race.
"It's all subjective at the moment until we get the cars apart and understand exactly what's caused the issue," he went on to comment.
"I suspect it's similar on both cars, because it's too close and too similar a failure."
Horner did clarify, however, that Verstappen's race-ending issue was not related to his reported steering struggles.
"The steering issue was when the car got dropped after the final stop; I think it's tweaked a track rod, so that's why it was slightly different left to right," added Horner.
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