Haaland hasn’t played since Sept. 19 with a unspecified muscle problem and will sit out Norway’s upcoming World Cup qualifiers against Turkey and Montenegro.

Haaland wished the team luck on Twitter on Monday ahead of crunch games for his ambition to play in Norway’s first major tournament since 2000.

“Fundamentally, all clubs have a duty to release (players)” for international duty, said Sebastian Kehl, the administrative manager for Dortmund’s team, in comments published Monday by the Westdeutschen Allgemeinen Zeitung newspaper.

“However, Erling is currently injured and hasn’t been able to play for us recently and also can’t take part in team training in the following weeks.”

Kehl said he expected the Norwegian federation to have “trust in us and in (Haaland)” over the injury.

Dortmund returns to action Oct. 16 against Mainz and “hopefully” Haaland will be fit enough to play, sporting director Michael Zorc told the newspaper.

That game could see the return of forward Gio Reyna, who is sitting out upcoming games for the United States, and midfielder Mahmoud Dahoud. If Haaland’s hoped-for return date slips back, it could affect Dortmund’s Champions League game against Ajax on Oct. 19.

Few players transform their teams as completely as the 21-year-old Haaland. He has 11 goals and five assists in seven games so far this season, and contributes to more goals indirectly by drawing defenders out of position and creating space for teammates.

With Haaland in the team this season, Dortmund averages nearly three goals per game. In the three games he’s missed so far with injury, Dortmund has averaged one goal. Fans have had to be satisfied with glimpses of him sitting in the stands or dressed all in black accepting a UEFA award on the field.

Dortmund has been here before. A muscle tear caused Haaland to miss seven games in December last year, coinciding with a 5-1 loss to Stuttgart which led to the firing of Lucien Favre as coach.

If Dortmund can’t overwhelm teams in attack, that puts more pressure on an error-prone defense. Over the last two weeks, Dortmund has coped without Haaland ? just about. A 1-0 loss to rival Borussia M?nchengladbach was bitter because of the lack of chances created, especially for Dortmund coach Marco Rose against his old club.

Following up with a 1-0 win over Sporting Lisbon and a 2-1 win over Augsburg was better, though neither opponent really challenged the Dortmund back line.

Other players could do with a break, too. Center-back Mats Hummels hasn’t been called up for Germany and said on Instagram on Sunday that “now there’s a bit of time again for me to keep improving my health and fitness condition.”

There’s alsoQ the looming question of Haaland’s future. His vast talent and young age marks Haaland out as an excellent long-term bet for any club which can afford his transfer fee and likely astronomical wages. Very few clubs have that kind of money, especially during the coronavirus pandemic.

Haaland’s father and his agent publicly explored links with some of Spain and England’s biggest clubs in April, but little has come of that since.

Dortmund risked failing to qualify for the Champions League at that time, but eventually did, keeping Haaland in world soccer’s biggest shop window.

Selling Jadon Sancho to Manchester United ensured Dortmund had the income to keep Haaland around for another season. Still, his future remains far from certain.