Shawcross checked in at the Three Lions' Watford training base for the first time on Sunday night knowing questions are being asked over his suitability to represent his country following his red card shame on Saturday.
The former Manchester United defender left the pitch in tears after being sent off for the tackle that broke Aaron Ramsey's leg, an incident Arsene Wenger believes was worthy of far more than the three-match ban Shawcross must now serve.
Pulis said: "While we are all deeply saddened at what has happened to Aaron, we believe that Ryan is worthy of this chance to represent his country and hopefully put himself in contention for a place in the England squad for the World Cup finals.
"It has been a difficult time for Ryan and he is still upset at the seriousness of the injury to Aaron.
"But it is important to remember what he has achieved over the past two years when he has emerged as one of the best young defenders in the country.
"The amount he has come on in that time has been unbelievable, so I always felt that if he produced a consistent level of performances for us this season, as he has done, an opportunity would come along sooner rather than later."