Steven Gerrard was taken aback by the quality and toughness of Major League Soccer.
"I don't think it was a question of his focus or commitment. I think he found the league to be more challenging that he expected," he said.
"He plays a very demanding position. When he came here to play us, it was 100 degrees and 90 per cent humidity. He found the elements to be challenging.
"In some cases, you have to come to Houston where it's 100 degrees.
"You go to Salt Lake or Colorado where you're at altitude and you have to deal with that, or you go to Toronto or Montreal where it's cold, or you go to Seattle or Portland or New England where you're playing on artificial turf."