The Irish full-back is free to play at Wembley after completing a three-match suspension last week and his availability is causing McAllister's biggest dilemma ahead of United's clash with Doncaster Rovers at Wembley.

Bradley Johnson has played on the left side of defence during the club's last three games, and McAllister would alter his side with great reluctance following their outstanding semi-final victory over Carlisle United last week.

The Leeds boss kept faith with the line-up which lost 2-1 to Carlisle during the first leg at Elland Road for the return fixture at Brunton Park, and he was repaid by the 2-0 victory in Cumbria which secured United's place in the play-off final.

Sheehan missed both semi-final games following his straight red card at Yeovil Town on April 25 – a dismissal incurred by a rash and unnecessary two-footed tackle on Yeovil's Lee Peltier – and McAllister is considering whether to recall on his only recognised left-back or leave Bradley Johnson in a defensive role.

McAllister said: "He (Sheehan) is relieved that he's able to come back into the squad, and this is the big part of my job.

"I've got three more training sessions to see the look in people's eyes, and then I'll make my decision on Saturday."

United have no other injury concerns and look set to travel to Wembley on Sunday with a full squad.