Borussia Dortmund forward Sebastien Haller said he was holding out hope of playing in his side's first competitive match of 2023, as he makes his way back from testicular cancer.

Speaking at the German side's winter training camp in the Spanish city of Marbella, Haller said he was doing his best to be fit for Dortmund's January 22 clash at home against Augsburg.

"Of course everything is possible. I've no restrictions in my mind. The only people who can give me restrictions are the coach and the medical staff," the 28-year-old forward said.

The France-born Ivory Coast forward said he would listen to the opinion of Dortmund's medical team.

"When everyone is of the opinion that it would be a good idea for me to play, then I'll play.

"Of course I want to be on the field every day play again as soon as possible.

"I will do my best to play on the 22nd (against Augsburg) and be in the best possible shape."

A January return would be a remarkable outcome for Haller, who only trained with the team for the first time on Saturday after returning from cancer treatment that included chemotherapy and two operations.

Haller, who has trained solo as much as medically possible during his recovery period, said the experience "was not easy" but added "you now realise that all the work over the past half year was worth it."

Haller has not made an appearance for Dortmund since joining the club from Dutch side Ajax in the summer.

"I get goosebumps (to see him) back on the field again,"  said Dortmund captain Marco Reus, who also expects to make a return, from injury, in January.

"We are just so happy that he is back again.

"The way he's fought back shows his mental strength. It's damn strong."

Haller could make an appearance from the bench in Dortmund's friendly against Fortuna Duesseldorf, on Tuesday afternoon in the Spanish seaside city.

The former West Ham striker's last appearance came for Ajax against Vitesse Arnhem in the final game of the 2021-22 Eredivisie season on May 15.

Haller is one of four Bundesliga players to have been diagnosed with testicular cancer in recent years, alongside Union Berlin's Timo Baumgartl, Hertha Berlin's Marco Richter and Jean-Paul Boetius.

Haller said he reached out to his fellow players during his treatment for advice and support.

"I spoke regularly with Timo Baumgartl, Marco Richter and Jean-Paul Boetius. Despite (us) having the same diagnosis, the illness impacts each person differently, but they still gave me some valuable tips."