Sunderland team news: Tony Mowbray explains Leeds United forward decision

Gelhardt has been a regular since his arrival in the latter stages of the January window, and has often been asked to lead the line on his own in the absence of Ross Stewart.

The 20-year-old has been used as an impact substitute in the last two games, with a mixture of player availability and tactical preference leading to Mowbray shifting to a system closer to a back three.

"It's really because we've played a back three in the last couple of games in terms of when we build up," Mowbray said.

"We've pushed Goochy up really high and Jack on the other side, it's not always easy to see the formation in a game but that's how we built up.

"It was just the players that we were playing into really, we wanted more control so we played almost with two tens rather than a centre forward getting marked by two big centre-halves because both of the last two opponents have had that - and it will be the same tomorrow night. Big centre-halves who want to mark a striker, win headers and defend.

"I had that discussion with Joe and he understood it, and it ultimately won't do him any harm for a couple of games to get half an hour from the bench. You'll have to see whether he plays against Huddersfield and what formation we go with but he's fine with what we've done, he understands why we did it."

Mowbray is weighing up a similar conundrum for Huddersfield Town's visit, knowing that Neil Warnock's side will, like Birmingham City, offer a significant threat on the counterattack and will look to expose Sunderland's need to force the issue and claim the three points.

Mowbray will be without Dennis Cirkin due to suspension and also revealed in his pre-match press conference that he has lost another player to a short-term injury.

Warnock's side have taken points from a number of top-half sides in recent weeks and while Mowbray will be aggressive in going after three points, he has stressed the importance of doing so in a sensible way.

"The conundrum for us is how many attack-minded players on the pitch tomorrow because we have to try and win the game," he explained.

"It's not much good for us to take a draw, so it's whether you did it later in the game, overload and get those attacking players on, or whether you start with them. But then you have to be careful that you don't leave yourself vulnerable to a counter-attacking team.

"That's the balance for us to find, you saw with Middlesbrough and Blackburn, they are very good teams who move the ball through the lines and yet they conceded goals quickly against a team they will have felt they were dominating. You do have to be careful, so it's been a delicate thought process in terms of picking the team."