Pascal Wehrlein says damage to the floor of his Manor MRT05 affected his performance at the Canadian Grand Prix, as he finished the race in 17th place.
Wehrlein picked up damage to the floor of his car on the grid but was still able to battle Renault's Jolyon Palmer and both Sauber drivers across the first stint of the race.
Wehrlein, however, once again struggled with tyre wear during the closing stages and slipped behind Marcus Ericsson, eventually coming home in 17th spot.
"I got a very good start and managed to leapfrog Palmer and keep both Saubers behind me before the first pit stop, although we had picked up some damage to the floor when we arrived at the grid and I was losing lap time," he said.
"By the time we got to the final stop I was struggling with the tyres and that allowed Ericsson to get past.
"I was still able to finish ahead of Nasr, which is positive, although it’s disappointing not to be able to hold off both."
Manor team-mate Rio Haryanto finished as the final classified runner in 19th position.
"The first part of the race went well for me. I was keeping up with my team-mate and also with Palmer and [Kevin] Magnussen ahead," he said.
"At the first pit stop I expected to rejoin the race and be racing with Ericsson but we had a problem which slowed the stop and I came out behind [Felipe] Nasr instead."