They re-signed striker Paul Eaton from Wealden and he was due to be in the squad for their match with Seaford on Wednesday.
Eaton struck 28 goals in each of Oak's last two seasons and had netted four this campaign before he joined Wealden, then managed by Andy Gander in October.
But Gander quit last month, and Eaton has followed fellow striker Danny Curd to Chalky Road.
Oak manager Anthony Whittington said: "It's great to get Paul back here. He went to try his luck elsewhere but it didn't work out and I'm glad he has come back here, rather than look elsewhere.
"Paul will strengthen us for the run-in, and he, or someone else, can help out the Reserves as well."