Irvine said: "Frank Simek put in a very good performance against two very difficult opponents. He saw Nathan Tyson off, which is not easy because he is rapid, and then had the misfortune of having Paul Anderson come on who is also very, very quick, but again coped very well with him.
"I've spoken to the medical staff and they don't think there's any problem with Frank playing game after game, so hopefully that will be the case. Frank is a really good professional so his preparation for the games will be spot on and his recovery after the games will be spot on as well.
"I knew all about Frank when I was working at Everton because we, along with a lot of other clubs were looking at making him a Premier League player - that's the level he was at then.
"Obviously injuries have been a setback for him, but hopefully he's over those problems now and can start rediscovering that kind of form. If Saturday's anything to go by then we do have a very good player here."