Jose Mourinho has questioned the attitude of his Chelsea players and stated that none of them are now “untouchables.” Chelsea visit his former club FC Porto in the Champions League group stage on Tuesday after yet another disappointing performance in the Premier League when they needed to come from behind to draw 2-2 at Newcastle United.

It was after leaving Porto for Stamford Bridge 11 years ago that Mourinho famously described several core members of his squad as “untouchables,” as he went onto win back-to-back Premier League titles in his first two years in charge. But this time around, Chelsea’s title defense has begun in woeful fashion. The London club has won just two of their first seven matches. And Mourinho has made it clear that he believes the way Chelsea responded when 2-0 down against Newcastle shows that the problem is simply down to his squad’s desire.

“When you play the way we did in the second half it’s because we can play that way,” he said at his pre-match press conference. “So I think it’s not a question of if we can, we need to want, and if we want, we need to want for 90 minutes. To be untouchable, you have to be a fantastic player but you have to be consistent, to be a winner you don’t need to win all the time, but to be a winner you must to have a strong mentality every game every day. And in this moment I don’t have untouchables.

“Clearly it's an attitude perspective of some individuals. And when you have individuals with that unstable attitude in terms of motivation, desire and commitment you will pay.”

At least things so far look brighter in the Champions League. In their opening match, Chelsea brushed aside the challenge of Maccabi Tel Aviv, 4-0. Their next match, though, carries particular significance for Mourinho. It was at Porto that he came to prominence as a coach, delivering the UEFA Cup in 2003 and then the Champions League the following season.

While Porto have not matched that ultimate success since, they have been regular participants in the latter stages of European competitions. That has been largely achieved on a strategy of signing little-known players before turning them into stars and often selling them on at huge profits.

There is evidence of that policy in the current squad, with the likes of Algeria international Yacine Brahimi and Mexico midfielder Hector Herrera impressing as Porto reached the quarterfinals of the Champions League last season. But they also veered away from the approach somewhat this past summer when bringing in veteran Real Madrid goalkeeper Iker Casillas. The Spanish World Cup winner has a very personal history with Mourinho, having never truly recovered his status at Madrid after being sidelined during the Portuguese’s time in charge.

Casillas’ time at Porto has begun encouragingly, with last season’s runners-up going six matches unbeaten in the Portuguese Liga to sit top of the table. In the Champions League they secured a 2-2 draw away at Dynamo Kiev. But Spanish coach Julen Lopetegui does expect things to be straightforward at the Estádio do Dragão, despite Chelsea’s domestic struggles.

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

“I have great respect for Mourinho. He has been incredible in his career, very important to Porto because of his great achievements at domestic and European level. We are talking about a Chelsea team that has top players and a top coach. We are a team with a lot of hopes, ambitions and belief, but they will push us to our limits.”

Kickoff time: 2:45 p.m. EDT

TV channel: Fox Deportes

Live stream: Fox Sports Go, Fox Soccer 2Go