Jose Mourinho has warned his Chelsea stars that finishing at the top of their Champions League group is no guarantee they will be able to make a serious challenge for the trophy.

Mourinho's side ensured it took first place in Group E with a 1-0 win over Steaua Bucharest on Wednesday, thanks to Demba Ba's first- half goal at Stamford Bridge.

But it was an underwhelming display from the Blues against a Steaua team which offered only token resistance and Chelsea boss Mourinho added to the downbeat mood by refusing to talk up his team's chance of emulating its 2012 triumph in the competition under Roberto Di Matteo.