Julen Lopetegui has praised Jose Mourinho's past achievements at Porto ahead of the Chelsea manager's return to the Estadio do Dragao.

The Portuguese led the Dragons to four domestic honours, as well lifting both the UEFA Cup and Champions League during his two years in charge.

Mourinho has enjoyed similar success at each of his clubs since, although he has hit a rough patch during his second stint at Chelsea following a poor start to the campaign.

Lopetegui has leapt to the defence of the self-proclaimed 'Special One', however, suggesting that the Blues will prove to be a real threat once more this season.

"I have great respect for Mourinho," he is quoted as saying by FourFourTwo. "He has been incredible so far, very important to Porto because of his great achievements at national and international level.

"Their league position does not influence their matches in the Champions League - they won their first game 4-0. They are a great team with great potential and we need to play really well, to our limits, and be technically and tactically perfect."

Prior to joining Porto in 2002, Mourinho spent time at Benfica and Uniao de Leiria.