Goalkeeper Trevor Carson has been recalled from his loan spell with Lincoln City by parent club Sunderland.
Carson moved to Sincil Bank in January and has made 16 appearances for the Red Imps, keeping four clean sheets.
Tilson now faces a race against time to find a replacement ahead of Friday's League Two clash with Rotherham United.
Joe Anyon is currently on loan at Morecambe and goalkeeping coach Paul Musselwhite is the only other shot-stopper on the books.
Tilson told the club's official website: "With there being a 24-hour recall in Trevor's contract, Sunderland were fully within their rights to take him back, although it does put us in a difficult position as we've only got until 5pm on Thursday night to bring someone else in.
"But I would like to thank Sunderland for allowing Trevor to come to us and play some competitive football.
"He's a great lad and on behalf of everyone here at Lincoln City I would like to wish him every success for the future."