Poland striker Lewandowski sat out Wednesday's (AEDT) session with a knee injury but joined his colleagues ahead of Bayern's home game against Fortuna Dusseldorf in the Bundesliga.

Kingsley Coman and Arjen Robben also joined in training as they recover from ankle and knee injuries respectively, with Davies' arrival giving coach Niko Kovac a boost.

The teenage winger has joined from Vancouver Whitecaps and will be available to play for Bayern after the Bundesliga's winter break.

"My first impressions of the training ground were great," Davies said. "As a kid I dreamed of being part of such a big club.

"Now I am and it's unbelievable. I'm very excited and looking forward to my time. I want to prove myself every day in training and work hard."

Bayern sporting director Hasan Salihamidzic indicated Davies will be ready to make his Bayern debut in January.

"We're excited about him," he told Bayern's website. "I'm sure he'll develop here at Bayern and help us. I wish him the best of luck and success."

Kovac could also have Thiago Alcantara back in his squad soon as the Spain midfielder completed laps at Bayern's training ground for the first time since tearing ankle ligaments last month.

"The first circuits around the pitch on Wednesday are a good step towards his comeback," Bayern said in a medical update on the club website.