Mercedes' head engineer Paddy Lowe remained hopeful his team will be able to fix Lewis Hamilton's engine, despite the reigning Formula One champion's failure to set a time in the opening practice session of the Malaysia Grand Prix on Friday.
Hamilton, who won the 2015 F1 season opener in Melbourne, was the only driver who was unable to complete a flying lap in the morning session at the Sepang International Circuit, stopping on Turn Eight after reporting a "click" in the back of his car.
While the 30-year-old was convinced he could have made it back to pit lane, Mercedes told him not to risk the race engine.
Despite their cautiousness, when Hamilton's car arrived back in the Mercedes garage, the mechanics appeared unable to fix the problem, prompting speculation they would have to make one of just three engine changes allowed for the season.
But Lowe - Mercedes' Executive Director (Technical) - told Sky Sports after the practice session finished that the team had yet to make a decision.
"There is a hardware problem that we need to go and fix, so we don't know exactly what we are going to do yet," he said.
"We need to do some investigations in the next few minutes to decide what we are going to do for P2."
When pressed on whether they would need a fresh engine, Lowe added: "No, not necessarily. We are hoping not."
Despite Hamilton's frustrating session, his Mercedes team-mate Nico Rosberg set the fastest time in Malaysia, stopping the clock at 1:40.124.