Leeds Carnegie have not confirmed that Senior will play for the rugby union club, but he will train with them as they begin their pre-season training ahead of the 2012/13 season.
However Leeds Carnegie head coach Diccon Edwards has not ruled out a possible code switch for Senior, who suffered a knee injury last year.
Edwards said: “We are delighted to welcome Keith into our group for pre-season training. The hope is that he can prove his fitness and we can then sit down with him and discuss the future after that.
“He has been doing a lot of training on his own because of the nature of the injury and it is good that we are able to bring him back into a team environment and I know that is something he is enjoying.”
But Senior is confident of playing rugby again, regardless of which code he turns out for. The 36-year old played rugby union before signing for Sheffield Eagles prior to the beginning of the Super League era in 1996.
Senior was due to play for Crusaders RL this season, but when the Welsh club’s Super League licence application was withdrawn Senior became a free agent.
He will use his time at Carnegie to get back to full fitness.
Senior said: “I would like to thank Chris Gibson and Diccon Edwards for giving me this chance to train with Leeds Carnegie.
“I know they are preparing for a big year in the Championship and hopefully as well as proving my own fitness, I can also help them out given my experience at the top level, albeit in a different code.
“I am still working hard with the medical team here at Leeds and I am confident I will be able to play rugby again.”
Senior underwent a knee reconstruction as a result of the injury he suffered whilst playing for the Rhinos.