The 30-year-old joined the League One outfit earlier this month, but it is understood that he has attracted interest from the United States.
"Jordan has an opportunity to go to America. I don't know how firm that offer is and that is a gamble we have to take," Curle told the BBC.
"Sometimes we are not able - because of the finances at the club - to offer big long-term contracts to players that are 30 or 31.
"But someone out there may be able to give them something that we can't - as in longevity in a contract."
Stewart has previously played for Millwall.