"I wouldn't say 'surprise' was the right word to use about Michael," said Frail. "But in a difficult situation, he's surpassed himself. Going from Hearts to Hibs and back to Hearts isn't something anyone had done for a long, long time. He's been arguably our best player this season and on Wednesday against Celtic he was the driving force alongside Marius Zaliukas and Ruben Palazuelos.
"Michael can see and make passes. He'll take the ball in any situation and his work rate has been first class. I knew he was a good footballer. You don't end up at Manchester United if you are not a good player.
"But he has surpassed expectations and definitely given us that little extra thing you need in midfield."
Asked about how the player had coped with the aggravation of living in Edinburgh and flitting back and forth between Hearts and Hibs, Frail grinned: "He loves it. I genuinely think he enjoys it all. Michael is quite a strong character when it comes to that side of things.
"Yes, I was surprised he would want to put himself through that. But he is a Hearts fan at the end of the day. I think he felt he had unfinished business here. He didn't fulfil what he wanted to achieve the first time round. He's certainly doing that now.
"The biggest thing is the way he has turned the Hearts fans around. They are all behind him. They have seen his performances and his work-rate. I am sure he will give the same on Sunday and, hopefully, he will want to put one over on Hibs."