Following Wednesday's FA Cup victory over West Ham United, Sir Alex Ferguson claimed that the 39-year-old will be extending his current deal, but Giggs refused to commit to another year when quizzed on the matter.
The former Wales international said: "I don't know if I'll have another year.
"I'm probably enjoying it now more than ever.
"If you don't enjoy the FA Cup at Old Trafford then you should pack it in, but we'll see what this season brings."
Giggs has played in every Premier League season for United.