The 29-year-old former Hull and Swansea forward cannot understand why his first-team chances were so limited after 15 goals in his first season with the club.
And with manager Mark Yates undecided whether he will offer Duffy a new deal the forward just wants to be playing regularly.
"If I get an offer elsewhere with more of a first-team chance then, of course, that will interest me more," he told the Gloucestershire Echo.
"I started six games in all competitions last year and never in a million years did I imagine that would be the case after scoring 15 in my first season at Cheltenham.
"It almost felt like a waste of a season and the manager may have felt I was lacking a spark, but I didn't have any chances to get that spark.
"I need to speak to him (Yates) to find out exactly what his plans are and then I can make an informed decision.
"After last season I want to play and I am not going to sit on the bench at Cheltenham for less money than I was on last year."