Bergwijn suffered a sprained left ankle in a 1-1 draw at Burnley on Saturday that stretched Spurs’ run without a win in all competitions to five games.
However, Mourinho is bullish Spurs can spring a surprise by overturning a 1-0 first leg deficit away to Leipzig on Tuesday to progress to the quarter-finals of the Champions League.
“I don’t expect him to play again this season,” said Mourinho at this pre-match press conference in Germany.
“We’re used to it. I’d say we were psychologically more down with the other injuries because this one, when you’ve got four or five injuries, to have six or seven is the same. No problem, we are very confident.”
Tottenham are eighth in the Premier League, seven points adrift of a place in the top four, and were knocked out of the FA Cup by struggling Norwich last week.
A run of poor results despite a depleted squad has raised questions over Spurs chairman Daniel Levy’s decision to sack Mauricio Pochettino in November and replace the Argentine with Mourinho.
Pochettino transformed Tottenham’s fortunes in five-and-a-half years in charge, but failed to turn that progress into trophies.
Mourinho has a stellar coaching CV having won 25 trophies at Porto, Chelsea, Inter Milan, Real Madrid and Manchester United and he is confident that he will also end Tottenham’s wait for silverware.
“I believe that Tottenham is not going to be my only club without silverware,” added Mourinho.
“I won at every club and I believe I’m going to do it at Tottenham.
“I’m here for three or four months. I get the team in a difficult situation, now the team is in an even more difficult situation for the problems we are having, but I believe in me, in the players, in the club and believe that during my contract I will help the club and the players to do it.”
In the absence of Kane, Son and Bergwijn, the onus is on Dele Alli to deliver the goals to keep Spurs’ season alive.
“This isn’t a time to get our violins out. We have to show our character now as a team, everyone has to step up,” said Alli.
“It’s been a difficult season but we have to keep believing.”
Kane returned to training on Monday, but the England captain is still some weeks away from a comeback as he recovers from hamstring surgery.
“It’s a massive boost. Even when he’s coming to games to watch the games, he’s always speaking and trying to motivate everyone, he’s a real leader,” added Alli.
“I don’t want him to rush it because I know how much it can come back, but at the same time we need him as well.”
