The 33-year-old linked up with the rest of the Welsh squad in camp yesterday as they prepare for the opening fixture of the tournament against England on Friday February 4 and the coaching team were full of praise for the country's top try scorer.
"Shane has been around for such a long time but he is a priceless asset for Wales, the Ospreys and rugby in general," said Howley.
"To have him back is something we are thankful for."
Howley's views were echoed by head coach Warren Gatland,
"Shane made a huge difference when he came on for the Ospreys last weekend," he said.
"He looked sharp and got his hands on the ball and created a try.
"No-one is going to be released this weekend, although we thought about giving game time to Shane.
"But it is important he does not get injured at the moment because he is pretty precious at the moment.