Harry Kane is an injury concern for Tottenham ahead of Sunday's north London derby against Arsenal after missing training on Wednesday.
The Spurs striker, along with Sergio Reguilon, Carlos Vinicius and Erik Lamela, were not pictured in training ahead of their Europa League clash at Linz ASK on Thursday.
When asked about their absence Mourinho confirmed in his pre-match press conference the quartet are injured, with Lamela having missed their past five games with a calf injury.
"I don't believe he [Lamela] has a chance for the weekend," Mourinho said. "Harry, Vinicius and Sergio there is a chance for them to be [fit] for the weekend."
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Mourinho then refused to reveal the nature of Kane's injury, but added there was a "good chance" the striker would return to face Arsenal.
He added: "I'm not going to tell you the nature of his injury. I think there's a good chance [for Sunday], I don't want to lie, I don't want to hide anything in relation to 'Oh is he going to play or not'. I think he's going to play, that's my feeling."
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Alderweireld in contention for Arsenal match
Meanwhile, Toby Alderweireld is back in training after missing the recent matches against Ludogorets and Chelsea with a muscle injury.
Mourinho selected Eric Dier and Joe Rodon at centre-back for Sunday's draw with Chelsea, and the Spurs boss admits to having options with Alderweireld in contention for Arsenal and Davinson Sanchez set to play on Thursday.
"He [Alderweireld] has a chance. Not for tomorrow, not even an option, but in this process of recovering he is doing very well and there's a chance he plays [Sunday]," Mourinho said.
"But Joe played against Chelsea and it was not an easy first match to play. Davinson will play tomorrow too so we have our options. If Toby cannot play we will not cry, and it will be a chance for another one."
A 'pony' in the PL race… what about Europa?
Spurs currently top the Premier League but Mourinho believes the club are still a "pony" in the title race.
With regards to the Europa League, where Spurs need a point on Thursday night to reach the knockout stages, Mourinho said they were "one of the most important horses".
However, he added the dynamics will change once the clubs who finished third in their Champions League group drop into Europe's secondary tournament, with Mourinho's former club Real Madrid among those currently third with one match remaining.
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"In the race for the Europa League, I think we are in the race, we are one of the most important horses in the race, we have to admit that," Mourinho said.
"An English team in the Europa League is for sure an important club. But then some important clubs are going to the competition later, which is something I never agreed, but is the way it is.
"Eight clubs that were not successful in the Champions League, instead of going home, they come to the Europa League, and then that will change the dynamics of the Europa League."
'No Dele problem; Bale issue only physical'
Mourinho went on to insist he has no problem Dele Alli, who has played more minutes in the Europa League than Premier League this season, while the Spurs boss stressed Gareth Bale's only issue is having the fitness to play consecutive matches in a short space of time.
"I don't make decisions about selling A, B or C, of letting D, E or F going on loan," Mourinho said. "I am responsible for the players that belong to my squad and are working with me. The ones that are not playing enough time in their mind, in their ambitions, they have only one thing to do, which is to use the time they play to show me they are better than the ones having more minutes. There is no secret with that.
"I don't have any problem with Dele, I don't have any problem with any one of the players. It's not about that, I'm really I don't have personal issues with any one of my players. Of course, players are happier when they play, they're not happy when they don't play.
"For that, I don't blame the players, that is the way it is, but again there is only one way for them to improve their situation, which is to work hard every day and use every minute they're on the pitch to try to improve their situation."
On Bale, who has started just one Premier League game but all four of Spurs' Europa League matches to date, Mourinho added: "The only problem with Gareth is to get him to the confidence of playing consecutive matches without any bad feeling, any negative feeling, without any remembrance of the recent past where the condition was not the best, and the fears were there.
"I think it's more about that, but he's playing regular and he has the chance of a physical evolution. Of course, he doesn't need a technical or tactical evolution, he just needs a physical evolution, getting to the intensity of matches, his confidence back to play consecutive matches, like three matches in a week. It's more about that."
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Keane doubts Spurs' title credentials
Asked whether Mourinho could steer Spurs to their first Premier League title since 1961, Roy Keane told Sky Sports: "He's done it before. His CV is fantastic.
"But I don't think these players he has at Spurs are good enough to win the title. They have the X-factor in Mourinho and Harry Kane, I don't think that's enough. They were hanging on at the end at Stamford Bridge.
"I think they are on for a very good season, but a very good season is a big difference to trying to win the league title. I don't think so. Manchester City are stronger than Spurs."