Football Manager 2017: 20 Essential Signings You Should Always Make

13. Kieran Tierney

Age: 19

Club: Celtic

Position: D (L)

Approx. Cost: £12m

Forget everything you know about Scottish defenders, because Kieran Tierney becomes one of the best young full-backs in the game. Celtic are crammed with quality youngsters in this year's game, and their star left-back stands out immediately.

Starting with excellent acceleration and pace, Tierney's determined (19) personality means he develops at lightning speed. He'll be an unstoppable presence on your left flank when he hits his stride, and after a single season, Tierney will be good enough to start for even the strongest top six sides.