"It means so much to Stevie to be winning things for his club and country and he came back from international duty on a real high," said the boss.
"We need him to be at his best and it is going to be very positive for his confidence to score two goals and play so well.
"We have had some difficulties so far this season, with the level of expectations and players reporting back at different times for the build-up to the campaign and Stevie has suffered from that, just like any other player.
"But England have qualified, so that is one less thing for him to worry about. The pressure is off. I feel sure that is going to be a positive thing for him and us."