Hull's relegation to the Championship could lead to a mass exodus at the KC Stadium and the next big star expected to leave is Croatia international Jelavic.
Jelavic is set for a move to Turkey with Trabzonspor showing plenty of interest and Hull are open to allowing the striker to leave in order to get him off the wage bill.
However, former goalkeeper Harper is not too keen on seeing Jelavic leave and has stated that the striker could prove to be an asset for the Tigers in the Championship.
Harper told the Hull Daily Mail: "They'll need to put the ball in the back of the net as well if they're going to get promoted. When (Nikica) Jelavic played last season the points total was in the twenties.
"He was a big player. Whether or not they can keep him remains to be seen but if they do have to sell up front, it'll be important to replace them with proven goalscorers."