Ramsey, 27, will see his current Arsenal deal expire at the end of the current season, and it is understood that the two parties are struggling to come to an agreement over a fresh contract.
Merson has urged the Wales international to sign a new deal at Arsenal as he might not be able to secure regular football if he decides to move on.
"I am shocked he is still there. He should just sign now. I thought Chelsea might come in for him. It is a massive football club. He plays every week for Arsenal. He could go elsewhere and might play 15 games," Merson told Sky Sports News.
Ramsey has scored 59 times and registered 57 assists in 333 appearances for Arsenal since joining the London club from Cardiff City in 2008.