The centre-half is currently on loan at Selhurst Park from Hull and is now a regular in boss Dougie Freedman's back four.
Palace are edging clear of relegation trouble in the Championship and Gardner, 29, will assess his situation once they are safe.
"My focus has been staying in the team, staying fit and getting results but I'm happy here and we'll see in the summer," he said.
"At the minute I'm just totally focused on playing and getting us up the league. But if the offer is there to stay I will definitely look at it."
Source: PA
Source: PA