The Arsenal manager heavily criticised Shawcross in 2010 when a tackle from the centre-back broke Aaron Ramsey's leg in two places, but Wenger has acknowledged that Shawcross should not suffer for his whole career after the tackle.
"What happened is what happened and it is down to Roy Hodgson to select the team. I think he has improved as a player and he has cleaned up his act," he said.
"You cannot convict a player forever because of that. I didn't agree at the time with the tackle. I said that, it was just my opinion again, it doesn't mean that the player has to suffer from that his whole life.
"He looks to be more efficient in his game and more composed."
Shawcross was included in Roy Hodgson's England squad for the World Cup qualifying matches against San Marino and Poland.