The Dutch keeper has missed seven games since sustaining the injury against Manchester City in October with Gerhard Tremmel taking his place in goal.
"I'm very happy to be out there with the boys on the training field," said the Holland international.
"I've done a lot of gym work and strengthening my groin with Richard (Buchanan) and Kate (Rees) from the physio team, and I feel very good.
"I don't feel any pain, but I know I am not quite 100 per cent yet, which is to be expected as I only got into full training today.
"But I think the main thing for me is to make sure I am absolutely ready before I am in contention to play. That is something I have learned in my career.
"We have some massive games coming up, and if I'm ready then that's great, but if I'm not 100 per cent then I won't put myself into contention for selection."
"It's great for me because I know Gerhard (Tremmel) is doing a great job, and that means I'm not rushing myself to get back to 100 per cent.
"It can be so difficult for a goalkeeper to come into certain situations because it's a very special position and different to the others, but Gerhard has come in and done so, so well."