Andrew Putnam (back) pulls out of John Deere Classic

Andrew Putnam withdrew from the John Deere Classic midway through Friday's second round due to a back injury.

Putnam, 36, started on the back nine and carded a double-bogey at the par-4 18th hole before pulling out.

He was 3-over for his round after opening with an even-par 71 on Thursday at TPC Deere Run in Silvis, Ill.

Putnam won his lone PGA Tour title at the 2018 Barracuda Championship. His best finish this season was a T6 at the RBC Canadian Open last month.