Jack Iredale could miss Cambridge’s FA Cup fourth round clash with Luton.

The in-form defender picked up an ankle injury in the 2-0 Sky Bet League One loss at Bolton on Tuesday.

Cambridge were left to sweat on the results of X-rays to uncover the extent of the damage, but Iredale’s availability on Saturday remains in doubt.

Sam Sherring would be poised to step in and pair up with Jubril Okedina in defence.

Harry Cornick could make his first start after calf trouble for Luton.

The forward climbed off the bench to net the winner in the 1-0 victory at Swansea on Tuesday and could now be primed to step into the starting XI.

Cornick was out of action for eight weeks with a serious calf tear but has returned to fitness and form.

And now the 26-year-old is keen to make up for lost time, starting with the weekend’s cup clash.