Borussia Dortmund suffered a major blow on Friday when Jadon Sancho, Raphael Guerreiro and Giovanni Reyna were ruled out of Saturday's Bundesliga game at champions Bayern Munich (12:30 p.m. ET, ABC/ESPN+), the club said on Twitter.
Winger Sancho and midfielder Guerreiro had been taken off with minor muscle injuries in their midweek German Cup quarterfinal win and have not fully recovered yet.
It was not clear why United States men's national team player Reyna had not joined the squad on the trip to Munich, although sources tell ESPN "it's nothing bad."
Sancho's absence is especially painful as the in-form England international has been sensational in 2021, scoring eight goals in all competitions while setting up another seven.
Sancho was also on target in their 1-0 win over Borussia Monchengladbach on Tuesday that sent them into the German Cup last four before being taken off.
Dortmund will therefore need to rely on Erling Haaland for their offensive production, with Bayern manager Hansi Flick praising the Norwegian's "winning mentality" and comparing him Bayern striker Robert Lewandowski.
"He's one you always have to keep an eye on," Flick said of Haaland. "He's like a centre-forward has to be. He embodies what Robert Lewandowski also embodies."
Haaland, who has 27 goals in as many games across all competitions this season, has been linked with a move from Dortmund should the club miss out on Champions League play next season.
"[Haaland is] hungry for goals. He has the pace; he's got the finishing qualities, and, of course, he has this mentality that he wants to win games, score goals," Flick added.
"If you look at the intensity of his 80-metres runs just to get in a position up front where he might be able to tap in the ball. It's top. It distinguishes him. He's one you always have to keep an eye on."
Bayern are top of the Bundesliga table on 52 points, two ahead of RB Leipzig. Dortmund have climbed back up to fifth place in the Bundesliga on 39 points having won their last two league games. They are three points behind fourth-placed Eintracht Frankfurt, with the top four finishers qualifying for next season's Champions League.
Dortmund have not won a league match at Allianz Arena since 2014 but Flick warned that his side will take nothing for granted against their great rivals.
"We are the league leaders and we want to protect our lead. We want to win the game and that is how we approach it," Flick said.
"Dortmund are more consistent now. The last days and weeks showed it. [Coach] Edin Terzic does a very good job. The last games have been consistent, the results are there. They have gained in confidence and you can see it."
Both Bayern and Dortmund are among the highest scoring teams in Europe. With 2.91 goals per match, Bayern have averaged more goals than any side in Europe's top five leagues and Dortmund's 2.09 goals per match rank them seventh ahead of Manchester City. However, both clubs have struggled at the back. Dortmund have conceded 1.35 goals per match and Bayern even more with 1.39 per match.
Flick also confirmed that Benjamin Pavard will not be fit in time for the match. The French defender was the latest Bayern player to test positive for the coronavirus and went into quarantine on Feb. 18. He has returned to individual training this week but has not yet trained with the team.
Reuters contributed to this report.