Rennie had played in eight consecutive Tests earning star reviews before dislocating a shoulder against New Zealand in the autumn internationals. It was another setback for Rennie, who has 20 caps, after knee problems that had previously kept him on the physio table.
"It has been a very frustrating season and I'm just looking forward to getting back on the pitch playing again," said Rennie.
"I've been trying to manage little goals and see improvements from day to month. The injury was not something I was used to and it was a case of making the shoulder strong and stable."
Had he featured during the RBS 6 Nations Rennie could be preparing to take his place on the British & Irish Lions tour to Australia this summer.
Instead he will be hoping to force his way into Scotland's plans for the summer tour of South Africa, but Rennie insists he isn't looking any further than the next game.
"It would be super to try to get back in that fold but I'm just concentrating on this weekend," he added. "I've taken the opportunity of the last few months to get fit and strong, rather than worry about the games that are on all the time."