Wales prepare to square off against Belgium in the quarter-finals of the European Championships on Friday night but as a cause of major concern for the Dragons, captain Williams was believed to be a doubt due to a shoulder injury.
However, Coleman has gone on to allay such concerns and has revealed that Williams will be fit in time to start the encounter against Belgium after suffering the problem in the Round of 16 win over Northern Ireland.
The Wales boss said: "We think it was when he fell after he collided with Jonny (Williams).
"He landed on his hand with a straight arm which was a bit of an impact on his shoulder.
"He's a bit bruised and sore, but he'll be fine and we'll get him on the grass as soon as we can. It probably won't be for the next day or two, but he is not a worry or a doubt and I would be surprised if he doesn't make the game.
"Ash being Ash he didn't want to come off and we were right. He thrives on it. All players at the top level want to play against top teams, where the excitement is, and Ash is no different."