The talented defender has not featured for The Potters since his infamous tackle with Aaron Ramsey that left the Arsenal starlet with a broken leg.
Pulis is eager for Shawcross to feature between now and the end of the season to boost his chances of making the England's squad for South Africa.
The Potters boss has confirmed Shawcross picked up a fresh injury to his foot in training, although he does not believe the injury to be too serious.
While Pulis is keen to have Shawcross back in his side as soon as possible he is against rushing him back into action and suffering a new setback.
"He's hurt his foot again," he told The Sentinel.
"He's gone in for a challenge in training and had a kick right on the spot, so there's no way we could risk him again.
"He's a very important player for us and we are determined to go carefully with him.
"We want him to go with England to South Africa, and if that were to happen it would be a great achievement for the lad and for the football club.
"But our priority is the team, and it won't do Ryan any good to put him back in before he's really ready."