They are familiar with the turbulence of life with Mourinho, who is competing at the Estadio do Dragao for the first time for more than eight-and-a-half years.
No great fanfare is anticipated for the manager who led Porto to unlikely Champions League glory in 2004. There is plenty of respect for his achievements, just no great affection.
Mourinho looked inside the museum on Monday night, and nodded his approval. After the scale of his achievements, he may expect more reverence, but this game is being trailed on national TV channel RTP1 as his reunion with Casillas.
Even so, Portugal is gripped by the Real Madrid feud which became a Spanish soap opera, rather than by any emotional homecoming.
‘He can have the friends he wants, I don’t care,’ shrugged Porto boss Julen Lopetegui, a former Spain international and Real Madrid goalkeeper like Casillas, who also played at Barcelona when Mourinho was on the coaching staff at the Nou Camp.
Chelsea’s problems, however, are more basic. More dropped points at Newcastle and the latest withering critique from their manager dominated preparations in Portugal.
‘We have no problems physically,’ said Mourinho. ‘Tactically it’s the same. Clearly it’s the attitude perspective of some individuals. And when you have individuals with that unstable attitude in terms of motivation, desire and commitment you will pay.
‘Generally I am happy and positive. They fight and want to improve, but we have some players who you want more from. I look for consistency. If not we become a Newcastle.
‘When Newcastle play Chelsea they play amazingly well, but when they play other teams they don’t play so well. This happens with most teams with an objective to stay between eight and 16th in the league.
‘They win today, draw tomorrow, three points here, one point there. But when you want to be a big team and you want to win you have to be consistent in your attitude.
There are two sorts of champions. There are champions who win something — and there are lots of them — but there are champions who during their career win one, two, three, four, five, 10 or 20 titles.’
Having won the Premier League in May, Chelsea have taken eight points from their first seven games. Mourinho said: ‘We have 25 champions from last year, but how many serial champions do we have? John Terry, John Obi Mikel, Branislav Ivanovic: almost every season they have something in the pocket.
‘I can be five or 10 years without winning a title, but I will still be a serial champion in my approach and my attitude. This is the problem we have at this moment.
‘I don’t demand that they’re champions every season. In this country that’s impossible, especially at Chelsea, because when we win the title it’s the end of the world and nobody is happy. But you can be a serial champion in your attitude. For me that’s just the point.’
Mourinho tried to shake his players from their comfort zone by dropping four of them for the 4-0 Champions League victory at home to Maccabi Tel Aviv.
They won against nine-man Arsenal and Walsall of League One but after rescuing a point at Newcastle, the manager said six of the team were below standard.
Mourinho did not name names, but said: ‘We are in an open situation. It is difficult to win the Premier League and Champions League, but possible. But if the season goes in one direction and becomes closed, and we can’t win, I will go just with the kids.
‘It makes no sense when you have nothing to win to play the older players. I’ll play the players we’re waiting for instead. I can arrive in a moment where I will look to the kids and say: ‘‘Let’s go, non-stop’’. I am ruthless.’
Porto can vouch for that. So can Iker Casillas.
