Maddison suffered a knee injury after scoring in last week’s 3-1 first-leg win against the Norwegian club.
After undergoing tests on the problem, the England international has discovered he will not feature again this term.
The 28-year-old’s absence is another setback in an injury-plagued campaign for the Premier League club.
Postecoglou is already without captain Son Heung-min due to a foot issue, although England striker Dominic Solanke has been declared fit for the second leg in Norway.
“Madders tweaked his knee in the first leg so he is out and will miss the rest of this season,” Postecoglou told reporters on Wednesday. “Yeah, disappointing for him because he’s been a big part of this latter part of the season for us, particularly in Europe.”
“He misses out but it has always been a constant of this season. Everyone else from the first leg travelled and is ready to go,” he added. “Disappointing for Sonny as well. He has progressed and there’s a possibility of him getting some game time at the weekend but he hasn’t trained with the team yet.”
Tottenham are bidding to win their first European trophy since the 1984 Uefa Cup and their first silverware of any kind in 17 years.
Languishing in 16th place in the Premier League amid talk that Postecoglou faces the sack at the end of the season, Tottenham goalkeeper Guglielmo Vicario said his team have got used to dealing with injuries throughout their turbulent campaign.
“We have to always deal with it to be fair. We will not have Sonny and Madders tomorrow, but it is on us,” he said. “The importance of the entire squad will be crucial.” (AFP)
