Fresh terms have been put to the 19-year-old midfielder, but no agreement has been reached as yet.
Wallace has attracted plenty of interest from the top end of the football food chain, with the likes of Stoke City, Leicester City and Brighton & Hove Albion all believed to be keen.
Pompey's standing in League Two means a departure is likely at some stage, but Wallace is in no rush to turn his back on the club that gave him his big break.
He is enjoying his football at Fratton Park and insists there is no chance of him seeking a departure in January or bringing to an end deal extension discussions.
Wallace said after finding the target in a 3-0 victory over Rochdale on Saturday: "I've been offered my first contract but with my family being away at the moment and being out of the team against Fleetwood, it put things back a little bit.
"I'll still carry on negotiating with the club and I'll definitely be here for the rest of the season.
"They have said they feel I'm a really important member of the team and I've said that I enjoy playing in front of all these people here that have believed in me from day one.
"I've got massive loyalty to the manager (Guy Whittingham), who gave me my chance in football, and you can't forget these things that happen during your career."