But Cardiff Blues coach Dai Young is delighted to welcome the three-times capped star back with several of his international stars rested for the Arms Park tie.
"Tom is a real star for us but has struggled with injuries this year. But he's back and he has seen Leigh Halfpenny doing so well so he will want to perform," said Young.
"It's great for us that we have such quality in that position now."
The Blues require a draw or better to seal a semi-final berth at Coventry's Ricoh Arena next March.
But Young has warned his stars of complacency against the English league leaders.
"Bath aren't top of the Guinness Premiership for nothing and we won't underestimate them.
"They're a quality team who can play an expansive game and if we give them any opportunities, they will punish us."
Cardiff Blues: B Blair; R Mustoe, J Robinson, T Shanklin, T James; N Robinson, J Spice; J Yapp, G Williams, T Filise, D Jones, P Tito (capt), M Molitika, R Sowden Taylor, M Lewis
Replacements: G Powell, R Thomas, S Morgan, M Williams, R Rees, C Sweeney, G Thomas
Bath: J Cuthbert; J Maddock, A Crockett (capt), S Hape, A Higgins; S Berne, S Bemand; D Flatman, P Dixon, D Bell, P Short, D Grewcock, A Beattie, J Scaysbrook, D Browne
Replacements: R Hawkins, A Jarvis, N Catt, S Hooper, J Faamatuainu, M Baxter, T Cheeseman