Sam Gallagher will be out for a while after injuring his calf in the 2-1 win over Middlesbrough.
Gallagher was forced off soon before the hour mark, with Semir Telalovic replacing him.
According to Jon Dahl Tomasson, the towering forward will now be out for five to seven weeks.
“We all know Sam Gallagher has a bad injury record, and I’m surprised he’ll be out for five, six, or seven weeks,” he said on RoversTV.
“We’ve received the report, and we’re very sorry for him and the team.”
“It’s always disappointing when a player is injured, especially for Sam, who has been injured a lot both before and after I arrived.”
“He’s a key player, and I feel bad for the kid because he wants to help the team.” He’s a fantastic young man with a fantastic mentality and approach, but we can’t change that.
“We need to consider our options.” We have Semir, who has recently come, Tyrhys Dolan, who has previously played in that position, Harry Leonard, who can play there, and we’ve tried Sammie Szmodics as a false nine there once.
“Ryan Hedges also performed there.” We need to make some adjustments in that regard.”
Gallagher has had a run of bad luck with injuries since joining Rovers, missing the first two of games of the season owing to a knock.
The 28-year-old earned his first start of the season in the Carabao Cup second round against Harrogate, scoring 8-0, and went on to play against Plymouth and Middlesbrough.
Lewis Travis, who was injured during the weekend, should be available to play Sunderland at Ewood Park.
Niall Ennis is still out but is expected to return to training next week, and Arno Sigurdsson’s recuperation is also progressing.
Following his summer transfer from CSKA Moscow, the Iceland international is yet to make his debut in a Rovers shirt.
Meanwhile, Jake Batty is expected to play for Mike Sheron’s Under-21 team against Hertha Berlin on Wednesday night at the Lancashire FA County Ground.
“We know Trav Lewis Travis is a warrior, a tough person, and I think he’ll be fine for tomorrow,” Tomasson added.
“We still have Niall Ennis out, but he will be training a little next week.” Sam Barnes is missing, but Jake Batty has trained with us and will make his Under-21 debut against Hertha Berlin on Wednesday.
“Arnor Sigurdsson’s appearance is improving. “The rest of the guys are prepared to go.”