Ralf Schumacher has cautioned that Charles Leclerc might "send Lewis Hamilton into retirement" this year.

Despite the buzz surrounding the seven-time world champion's switch to Maranello, 40-year-old Lewis Hamilton arrived in Melbourne noticeably slower than his teammate.

He ultimately qualified P8, one spot behind Leclerc.

"The Italian media will get very agitated after a certain amount of time if Lewis doesn't perform well enough," Schumacher told f1-insider.com.

"Does he want to put up with that? The likelihood is therefore not small that Leclerc will send Hamilton into well-deserved retirement."

Hamilton lagged further behind Leclerc in Melbourne's earlier practice sessions, but team principal Frederic Vasseur remained steadfast.

"I have absolutely no doubt that Lewis will perform, and very soon," the Frenchman told Sky Italia. "Last year, Carlos was P8 or P9 in FP1 and then he won the race.

"Lewis is still building a relationship with the team. It's not a long process, but one we have to go through. We can't expect too much at the beginning - we have long-term goals. But I'm very optimistic," Vasseur added.

Hamilton noted at Albert Park that he's "adapting" his driving approach to fit his new red car, a sentiment Vasseur echoed: "The goal is not to be at the limit, but to learn the mechanisms of the team.

"I am not worried and I have no doubt that Hamilton will find all of his speed soon. When you join a new team, you go through a transition period where you lay the foundations, and that's what we've done in these two months.

"It takes time to sort everything out."