Celtic winger Mikey Johnston joined West Bromwich Albion on deadline day for the remainder of the campaign and has already made an impact at the Hawthorns Stadium. Earlier this week, the Republic of Ireland international netted on his first start for the Baggies with a smart finish inside the area, which contributed to an eventual 2-0 victory over Birmingham City in the Sky Bet Championship. Despite his trickery, Johnston has been a hard player to quantify in a Celtic jersey over the years, with concerns over his end product and fitness issues taking their toll on his confidence. Brendan Rodge…