The former Carlisle United, Blackpool and Charlton shot-stopper has yet to play a first team game for Newcastle but is still expected to commit his future to the club.
Sir Bobby told the Evening Chronicle: "We have let John Karelse go and while we have some excellent young keepers coming through, we still felt we needed a third experienced keeper as cover for Shay Given and Steve Harper.
"We have offered Tony Caig a contract and it goes without saying we hope he signs it."