Smith’s side swept the Toffees with a second-half blitz in which Matty Cash and Leon Bailey scored, the latter also forcing a goal against his own side of Lucas Digne.
At this point, McGinn had been replaced by Marvelous Nakamba having complained of feeling dizzy.
Smith was asked about the circumstances in his post-game interview with Sky Sports and said: “He’s doing fine, I think it was the first corner where Tyrone [Mings] got the header.
“He got a blow to the head, I think he faced Keane and he just felt a little stunned. He said to me before, the first break ‘If I’m still dizzy I’m going to have to scream at you’.
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“He had another blow, he felt good to continue. After that he did another run after about 25 minutes there was a break in the game he came over that’s when he alerted me and I told the doctor , that’s why we did it then.
“You are guided by the player, he didn’t show any concussion symptoms as soon as he did. Just one hit on the head, there was another one later that he certainly told us.
Smith also played down concerns about Bailey’s fitness. The Jamaican was only on the pitch for 21 minutes – replacing Matt Targett, having a hand in two goals, and then being replaced by Ashley Young himself.
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“It’s really special,” Smith said of Bailey’s display. “He’s a really good player, that’s why we have him here at the football club, but on top of that he’s also a really good boy, the guys love him in the locker room.
“He’s really humble and a great person. We know he’s going to be a special talent for us.
“We hope it’s just a tight thigh, that’s what he told the doctors, so we didn’t need to take the risk then. We hope we just caught it on time and it’s a tight quad.
Matt Targett felt an injury at the kidnapper at half-time before leaving Bailey after an hour.