The 21-year-old Perth-born utility played through pain towards the end of Middlesbrough's season, even when Boro's promotion hopes evaporated with two games to play.

Verbeek told The West Australian he was furious with Strachan's decision to persist with Williams.

"Strachan let him play with injections and I think it's the worst thing you can do as a manager - let a player of his age play with an injection," he said.

"He even let him play when they couldn't reach play-offs anymore."

Verbeek acknowledged Williams was allowed to return to Perth before Boro's final Championship encounter with Leicester City but the Dutchman still wasn't impressed.

"The surprise I had in this case is he let a player like Rhys play in a dead rubber game and he knows he's injured," Verbeek said.

"I'm happy that Rhys survived and let's hope he is fit (for the World Cup)."

He continued: "I think Rhys did enough for Middlesbrough. He played for five, six weeks with an injury and he had an injection every week.

"I think Strachan should have known how good it is for a player to go to the World Cup. He showed no respect at all towards Rhys and I think that's bad management. I could not understand that.

"Strachan had an unbelievable career as a player, so he should understand how important it is for a player to go to the World Cup. He made it very difficult for him.

"I was a club manager myself so I know how difficult it is. He's not focusing on Australia, he doesn't care at all about Australia."