Lotus is sure Romain Grosjean had the pace to help prevent it losing second in the constructors' championship after the Spanish Grand Prix had his suspension not failed.
Grosjean was running ninth in the first stint, but had to park with a problem on his car's right rear on lap eight.
Although Kimi Raikkonen finished, Lotus dropped behind Ferrari to third in the teams' standings as the Italian squad secured first and third with Fernando Alonso and Felipe Massa.
Lotus chief Eric Boullier apologized to Grosjean for the issue.
"I think we suspect suspension component failure. It was not his fault and we feel sorry for him and for the team as well because we lost second place in the championship, and I think Romain was in good shape to finish in good points."
Lotus said it was the first such failure of a well-tested suspension configuration, and would be investigated in the coming week.