Ajax coach Frank de Boer is hoping he can persuade defender Jan Vertonghen and goalkeeper Maarten Stekelenburg to stay at the Amsterdam club.[LNB] Belgium international Vertonghen has been linked with both Manchester City and Arsenal, and recently hinted he would consider a move away from Amsterdam.[LNB]He has a contract with Ajax until 2013, but De Boer is optimistic the defender can be persuaded to extend that.[LNB]"I asked him to sign and he was positive about it," De Boer told De Telegraaf.[LNB]"Danny Blind (Ajax's technical manager) will soon hold talks with his agent.[LNB]"Jan has indicated he would move to any club, but for now he is at Ajax and seems to be happy here.[LNB]"I've given him a picture of what can happen if we stay together for another two years and then maybe he can get a better transfer."[LNB]The picture is less clear where Stekelenburg is concerned.[LNB]The 28-year-old will be out of contract next summer and De Boer is keen to quickly sort out the Holland international's future one way or the other.[LNB]"There is currently no interest in him," the coach said.[LNB]"We want to clarify whether he is staying or not and whether he wants to extend his current contract. If not, then a winter transfer seems probable."