FORMER Celtic defender Kieran Tierney is set to make his debut for new club Arsenal against Nottingham Forest in the League Cup tonight.

The 22-year-old joined the London club for £25 million this summer but is yet to make a first-team appearance as he recovered from a groin issue.

However, after a return to first-team training, Arsenal boss Unai Emery has now handed Tierney his first start since signing a five-year deal at the Emirates Stadium.