Sunderland hope specialist treatment has solved Lee Cattermole's injury concerns.
Cattermole missed Sunderland's defeat to Southampton a fortnight ago after succumbing to a groin problem in the previous weekend's encounter against Everton.
The 27-year-old had been carrying the injury for several weeks before it finally ruled Cattermole out of action, and he visited a specialist during the international break, who diagnosed the pain was stemming from a nerve pushing against a disc in his back.
A course of treatment appears to have paid dividends with Cattermole returning to full training today and in line to feature in Monday night's trip to Crystal Palace.
Sunderland boss Sam Allardyce said: "There was a slight problem he had with his back, that we've now cured or seem to have cured.
"He trained today and said he feels great, better than he has all season.
"I think there was a bit of an impingement in the back that had been there a considerable amount of time and maybe that took a little bit of the edge off Lee.
"I hope that won't be the case now."
Cattermole had started every game of Allardyce's tenure prior to the Southampton clash and the Sunderland manager has stressed the importance of the Teessider to the Black Cats' survival challenge.
Allardyce, who has a fully fit squad to pick from at Selhurst Park added: "We all know how important he is.
"His general enthusiasm, his drive and his willingness to try to win rubs off on everybody.
"So I hope he stays fit and gets back to performing as we know he can, as well as many other players who have a huge amount of Premier League experience.
"I keep saying to the lads you've really got to draw on that now, as much as you possibly can, to make sure we get out of trouble."