David Moyes has revealed that Ryan Fredericks was substituted against Newcastle because he sustained a groin strain.
The right-back was withdrawn after 45 minutes against the Magpies. 
It is fair to say that he struggled to contain the threat posed by Ryan Fraser throughout the game, and the introduction of Johnson somewhat steadied the ship defensively.
Johnson has played 12 times in the Premier League thus far this season but has been on the bench for some time in recent weeks.
The 22-year-old had been on the bench for five successive games, against Norwich, Leeds, Manchester United, Watford and Leicester, but could now start this weekend against Wolves after being involved against the Magpies.
Moyes has confirmed that Fredericks’ performance was not the reason for his substitution, but he has confirmed that he is fit to play against Wolves this weekend.
The boss has refused to give anything away in regards to who will play at right-back this weekend and told reporters, per Football.London: “I am the one who makes the calls. Ryan picked up a groin strain, not too bad, but we have Ben who is a young and progressing player and he ahs done really really well, left-back, right-back and done well and we like him a lot.”
