Bayern Munich defender Philipp Lahm has not ruled out retiring next summer

The former Germany captain, who retired from international football after lifting the World Cup in 2014, still has just over 18 months left to run on his contract, but he admitted he may not actually fulfil it.

"I wouldn't rule anything out," Lahm told Sport Bild magazine. "I said nine months ago already that this situation could arise and nothing has changed in how I see this."

Lahm, who turns 33 on Friday, previously stated that he could hang up his boots in 2017, if not a year later in 2018.

He has no intention of extending his current contract, although he does hope to be able to win another Champions League title before ending his playing career.

Bayern, who lead the Bundesliga on goal difference from Leipzig after 10 games of the season, are already through to the knockout stages of the Champions League with two group games to spare.

"I want to be able to measure myself at the very highest level and be able to recognise myself when the right time is to end my career," added Lahm.

"I certainly won't be determining my future only based on the number of titles we have won at the end of the season, but I will listen to my body and then decide how things go on."

Lahm has won seven Bundesliga titles, six DFB-Pokals and has one Champions League title in addition to the World Cup he won with his country in Brazil.