Daniel Farke on Leeds United injury concern for Sunderland and sub's Blackburn Rovers effort

The left-back, who recently returned to fitness from a minor hamstring strain, felt discomfort in a similar way during the second half at Ewood Park, having made a challenge on the touchline. Byram stayed in a seated position, asking referee Bobby Madley to halt the game and though he returned to his feet and did not have treatment, he was soon substituted.

"He felt again after, a long stretch, something in his hamstring," said Farke at full-time after Leeds won 2-0 to go seven games unbeaten in the Championship. "We'll have to assess him. Could be he's out for this week or at least the upcoming game. I hope it's not too bad. I had to play Djed [Spence] out of his position, at left-back for the first time. There is a concern for Sam for the next two games at least."

Leeds' next game is a Tuesday night trip to play-off hopefuls Sunderland, before next Saturday's Elland Road meeting with Coventry City. Farke will hope to have centre forward Patrick Bamford back, having had to make do without him at Blackburn due to sickness. Bamford's absence, and an international call up for Ian Poveda, allowed Farke to put Joe Gelhardt and Mateo Joseph on the bench in Lancashire, and it was the latter he turned to in the late stages to replace Georginio Rutter.

"Patrick was unwell so he was not involved due to illness," said Farke. "Mateo got his chance today and as a young player you have to wait patiently, work hard on the training pitch and that's what he did. If you get the chance you have to be on it, whether it's nine minutes or nine seconds.

"He had to show some physicality, he won some throws and free-kicks. It was not a moment to shine too much but overall a really important shift for the team. I told this to him straight after the game, I was pretty happy."