The centre-back made his first appearance since the summer operation - which he underwent in a bid to clear up a long-standing problem - when he played the first half of the development team's 1-1 draw at Port Vale.
And Shawcross told The Sentinel: "It was always planned to play 45 minutes
I've got a few niggles just from coming back so I need to let them settle down and hopefully I can kick on again next week.
"I felt good
It's just a case of building on it now
Hopefully next week I can get a 70-minute game in and then move on to a full game in the coming weeks.
"It's up to the manager (Mark Hughes) to see when I can get back involved
I haven't trained with the first team yet so I'll look forward to doing that.
"But I will stay with the under-21s for probably another week or so
It's all about game time and then we'll see after that
At the moment I'm trying to make sure I get the right minutes and the training between them is right."
The 28-year-old added: "It's a relief after quite a while of being impinged that I can move freely
My day to day life has been a lot better and it's been quite nice
I can pick up my kids again.
"It had got to the stage where it was getting a bit silly
The right decision was made
Unfortunately I've missed a bit of football but it had to be done."
Source : PA
Source: PA