Ryan Nyambe is one of two Rovers players currently self-isolating, with Daniel Ayala facing up to a month out with a hamstring strain.

Neither were included in the squad for the weekend win at Birmingham City having come off injured in the defeat at Huddersfield Town four days earlier.

Tom Trybull was also forced off at The John Smith’s Stadium, but did make the squad at St Andrew’s, replacing Lewis Travis for the closing stages after the 23-year-old made his return to action after three months out with a knee injury.

Travis follows Bradley Dack in returning to the squad after long-term injury, meaning Rovers’ issues now lie in the defensive positions.

Nyambe came off at Huddersfield Town with a sore hamstring, but Mowbray said he missed the weekend owing to a period of self-isolating.

Ayala faces a month on the sidelines, adding Rovers’ issues at the back, with Derrick Williams and Scott Wharton set to miss the remainder of the season.

Rovers kept a seventh clean sheet of the season on Saturday, and first since the November 24 win at Preston. They won three and drew two of the five matches that Wharton started, and the 23-year-old has been a miss having impressed alongside Darragh Lenihan, Rovers' last senior central defender standing.

That will see Rovers turn their attention to the loan market this month in a bid to add defensive cover to their ranks.

“We did a debrief of the season so far and Wharton’s performances alongside Lenihan had helped us to the most wins and clean sheets. He’s been a big loss to us," Mowbray said.

“Derrick Williams, very experienced, an international footballer is out in the same position, left centre half and I don’t think he’ll be playing again this season.

“He’s had an operation and I don’t think he’ll play again.

“We’ve been playing Bradley Johnson, a central midfield player at left centre half and we will probably go into the market.

“Daniel Ayala, three or four weeks, he’s strained his hamstring playing a second game in three days.

“In Daniel’s defence that was the fourth of fifth game he’d played this year, and playing that second game in three days has probably seen him break down.

“Ideally we’d have put him in and taken him out, played him alternate games for a bit until he got up to speed.

“Nyambe is isolating, Joe Rankin-Costello is going to be about another six weeks and he’s unavailable as well.”

Rovers are yet to comment on the absence of Lewis Holtby from the matchday squad on Saturday.