Muldoon signed for the Stones at the end of September, but hamstring and knee injuries limited him to just seven appearances.
Muldoon, who played for Charlton Athletic and Gillingham prior to arriving at the Gallagher Stadium, will join team-mates when training resumes at the end of June.
Manager Jay Saunders told the club`s official website: “Ollie’s someone with a lot of ability but unfortunately we didn’t get to see much of him through injury.
“He’s got the next six or seven weeks to get himself right. If he does, there’s the chance for him to get the pre-season he missed out on last year and put himself in contention for a place in the squad.”
Muldoon said: “I’ve not really had an injury before that’s kept me out for a lengthy period of time and not being able to get going and get fit is very frustrating.
“I didn’t have a pre-season, so I was always trying to play catch-up and it’s just been a very frustrating time for me personally trying to come to terms with being injured and not being able to train and play games.
“It’s not nice but you’ve got to adapt to that and work even harder to come back”.