Former Nebraska state Treasurer Shane Osborn, a decorated naval aviator, said he is “undoubtedly interested” in running for the GOP nomination to succeed retiring GOP Sen. Mike Johanns.

In a Wednesday interview with CQ Roll Call, Osborn said he has received many encouraging calls to run since Johanns shocked Nebraska Republicans with his retirement announcement Monday.

Republicans see Gov. Dave Heineman as their most formidable candidate for Johanns’ seat, and many potentials candidates are waiting for him to decide before they make a move on the race. A spokeswoman for Heineman told CQ Roll Call in a Wednesday email, “The Governor is taking a very serious look at it.”

Other names on the GOP radar include state Attorney General Jon Bruning and state Treasurer Don Stenberg, who both lost bids for Senate in 2012; plus the state’s three House members, Reps. Jeff Fortenberry, Adrian Smith and Lee Terry; and businessman Pete Ricketts.

Fortenberry already acknowledged his interest in the race.

Osborn became famous in 2001 when, as a naval aviator, a plane he piloted collided with a Chinese plane in international waters.

CQ Roll Call rates this as a Safe Republican seat.