MacDonald has signed a two-and-a-half year deal to stay at the Hawthorns (Getty Images)

The 23-year-old, who has signed a two-and-a-half year contract, has spent a year on loan at Albion, who have now agreed to pay �200,000 for him.

"Sherjill has got talent and potential. We need to work with that and make him a big asset," boss Tony Mowbray said.

"When you've got someone with the ability Sherjill has to beat an individual, you shouldn't discard him."