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.
Young said: "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.
"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 in Coventry next March. But Young has warned his stars of complacency against the English league leaders.
He said: "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 have won their last five matches in all competitions. The Blues are unbeaten at the Arms Park since Edinburgh won there 11-10 in the Magners League on 4 January.
Cardiff Blues have won their last three games in the EDF Energy Cup and have never been beaten at the Arms Park in the competition. The Blues have won the last five games they have played against English teams.
Bath Rugby have won their last two games since their 16-18 defeat in Toulouse in the European Cup on 12 October, this represents their only away loss this season.
The only previous meeting between the two teams was at the same stage in last season's EDF Energy Cup where the Blues won 14-6 at the Rec. Bath's last visit to the Arms Park was on 16 November 1996 in the quarter-finals of the European Cup with Cardiff RFC winning 22-19.
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, M Lewis, R Sowden Taylor
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, D Browne, J Scaysbrook.
Replacements: R Hawkins, A Jarvis, N Catt, S Hooper, J Faamatuainu, M Baxter, T Cheeseman.