The Potters have made six summer signings and, reporting he had a fully fit squad, manager Mark Hughes emphasised the point ahead of Saturday's Barclays Premier League opener at home against Aston Villa that several senior players he has every intention of retaining would not be able to feature.
In the end, the likes of Robert Huth, Jon Walters and Steve Sidwell were unused substitutes, while Victor Moses, Peter Odemwingie, Geoff Cameron and Andy Wilkinson were among those not in the matchday 18.
Stoke lost the contest 1-0 after Andreas Weimann netted in the 50th minute, and 26-year-old Holland full-back Pieters said of the hosts' performance: "Of course you are disappointed to concede a goal.
"But it was early in the second half, so you have a lot of time to recover and get back into the game if you keep playing football
But we were just too sloppy
We weren't sharp enough.
"The thing is, we have a big squad now
Everyone knows that and you have to perform every week.
"If you don't it is simple - you are out
We have enough players to take your place in every position
It is good for the team."
Asked if he thought the new players needed more time to gel with their team-mates, Pieters added: "I don't think they have time.
"It is the Premier League and you have to be there from the start
If you are not, then you have to look in the mirror and say you have to do better."
Stoke announced their latest new signing just prior to the Villa match, with Nigeria winger Moses - who was ineligible for the game - joining on a season-long loan deal from Chelsea.
Hughes has subsequently indicated there will be no further additions to the squad in this transfer window and that "one or two" players could be departing.
"It's fair to say, I think our business is done now," Hughes said on www.stokecityfc.com.
"One or two players may be leaving the club but I don't envisage anyone else coming in
We're done now - it's a case of working with the group that we've got."
Regarding 23-year-old Moses, Hughes said: "We're very happy that Victor has come to the club.
"He's a player with a great deal of potential but he hasn't played as much football as he would have wanted to in recent years.
"He's desperate to play and that's why he has come to us
He's a good young player and will bring pace and power."
There has also been plenty of change at Villa, with Colombia midfielder Carlos Sanchez arriving on Friday as their most recent summer acquisition.
At the same time as five new summer recruits coming into the picture, there have been personnel restored to first-team contention after long periods of not being involved, including defender Alan Hutton.
As part of a determined display by Villa's defence on Saturday, Hutton was making his first competitive appearance under manager Paul Lambert after two seasons of being frozen out and playing on loan.
And the 29-year-old Scotland international was delighted with how his "second debut" went.
Reflecting on the victory, Hutton said: "First and foremost you have to defend well, and to get a clean sheet was brilliant
All the boys are happy enough.
"It is unbelievable to come away from the Britannia Stadium with a win, being as hard a place as it is to get three points.
"And with it also being a second debut for myself, it was brilliant.
"Obviously it is difficult (being out of the first team for so long), but you just work hard and try your best, and when you get given a chance you have to take it."
Source : PA
Source: PA