Looking to continue their fine run of form, Arsenal instead endured a nightmare start to their Capital One Cup fourth-round match at Sheffield Wednesday on Tuesday. After a heavy schedule of important fixtures and with more to come, Arsene Wenger had made eight changes to his lineup in an attempt to keep his key performers fresh and injury free. Yet within 20 minutes at Hillsborough, he was counting the cost of two injuries.

First came Alex Oxlade-Chamberlain, who went down with an apparent tight hamstring after only five minutes. Improbably things were soon to get worse, when less than 15 minutes later Oxlade-Chamberlain’s replacement, Theo Walcott joined him in collapsing to the turf while grimacing in pain. For Walcott the problem appeared to be to his calf, with a suggestion that he had failed to be given time to warm up sufficiently when coming off the bench.

Whatever the cause, the injuries left Arsenal desperately short of experience in their attacking ranks. French 17-year-old Ismael Bennacer was Walcott’s replacement, joining Alex Iwobi and Glen Kamara as debutantes on the field for the Gunners.

And Sheffield Wednesday took full advantage of the disruption to their opponents’ ranks, going up 2-0 before halftime thanks to goals from Ross Wallace and Lucas Joao. It left Arsenal with a mountain to climb in the second half, but more of a concern to Wenger than a place in the Capital One Cup fifth round will be the condition of his two injured players.

Walcott has been in fine goal-scoring form of late, while Oxlade-Chamberlain has been in the side in place of the injured Aaron Ramsey. With matches against Swansea City, Bayern Munich and local rivals Tottenham coming up in the next two weeks, it is far from an ideal time for Arsenal to be suffering an all-too regular injury crisis. Yet, with Jack Wilshere, Tomas Rosicky and Danny Welbeck already on the sidelines, that is exactly what they could be facing.