The midfielder had been suffering with a slight hamstring problem and after undergoing scans on international duty was sent home to recover.
However, he is fit enough to play for the Blues who look to make it 12 games unbeaten in the Premier League this season against the Baggies.
Diego Costa is also fit enough to start after Vicente del Bosque left him out of the Spain squad so that he could get over his injury troubles. Jose Mourinho makes just one change from the team that beat Liverpool 2-1 earlier this month, with Willian in for Ramires, who drops to the bench.
Alan Irvine has made four changes to the team that lost at home to Newcastle before the international break.
Claudio Yacob comes in for Sebastian Pocognoli, Chris Baird and Craig Gardner take up places in midfield, with Youssouf Mulumbu and James Morrison missing out, while Graham Dorrans comes in for Victor Anichebe.
Chelsea: Courtois, Ivanovic, Cahill, Terry, Azpilicueta, Matic, Fabregas, Willian, Oscar, Hazard, Costa.
Subs: Cech, Zouma, Luis, Ramires, Schurrle, Drogba, Remy.
West Brom: Foster, Wisdom, Dawson, Lescott, Yacob, Baird, Gardner, Brunt, Dorrans, Sessegnon, Berahino.
Subs: Myhill, Gamboa, McAuley, Morrison, Anichebe, Samaras, Ideye.