The Dutchman has started 33 of Stoke's 36 Premier League games this season, but was left on the bench on Saturday as Tim Sherwood's side won 1-0 at the Britannia Stadium.
Pieters was impressed with the performance of Muniesa, who has started five games at either centre-back or left-back this season.
With captain Ryan Shawcross suspended for Saturday's home fixture with Fulham after being sent off against Tottenham, Muniesa could move to central defence, allowing Pieters to return at full-back.
"'Muni' played really well against Spurs marking Aaron Lennon, a good, quick player," Pieters told the Stoke Sentinel.
"He had a really strong game in my opinion. It's a good, healthy rivalry between us. I want to play and he wants to play, so we will have to see what the gaffer decides.
"Maybe he will choose to put me on the left and Muni in the centre - I think that's a good choice!
"He's my friend. We came here together and we will be friends, always."
