Robert Lewandowski hopes 2017-18 can still prove to be a successful season for Bayern Munich after a slow start prompted the club's hierarchy to replace Carlo Ancelotti with Jupp Heynckes. 

Bayern won the Bundesliga in Ancelotti's first campaign in charge last term but the experienced Italian coach did not fully convince at Allianz Arena.

A difficult pre-season was followed by dropped points in the league and a chastening 3-0 loss to Paris Saint-Germain in the Champions League, a result that sealed Ancelotti's fate.

Heynckes, who steered Bayern to their most recent success in that competition in 2012-13, has come out of retirement to answer the club's distress call.

And while Lewandowski knows they are already playing catch up to Bundesliga frontrunners Borussia Dortmund, he remains optimistic about the team's chances.

"Now there's a new season and a new challenge with the new trainer," he told ESPN. 

"Sometimes it's not so easy if you are at a club that changes trainer during the season. But we have to push on now. We are five points behind Dortmund, but there are a lot of games left until the end of the season.

"But in the Champions League, after our defeat at PSG, we have work to do to qualify. We have to play to the end. Who knows? Maybe we will win the Champions League and the Bundesliga."

Lewandowski won the Bundesliga twice at Dortmund and three times with Bayern, while also tasting DFB-Pokal and DFL-Supercup glory, but he is yet to get his hands on the biggest prize in European football.

Before defecting to Die Roten, the striker was on the losing side when Bayern defeated Dortmund 2-1 in the Champions League final at Wembley.

"Yes, after winning the Bundesliga and DFB Pokal a lot, you have to start thinking about other trophies," he said of his ambition to capture UEFA's elite club competition.

"Last season, we were disappointed because we knew we were playing well but sometimes in football a poor few minutes means you are out of the Champions League."