The Iceland international has made four Premier League appearances for the club, but has yet to make a start.
Pulis said in The Sun: "His weight is still a bit up on what it needs to be. Hopefully sometime in December we should have him up and running.
"The pace of the Premier League now dictates you have to be 100 per cent.
"He's good to have around the place and shown glimpses of what a player he is. But he's not up to the level we want."