kLR 650 C clutch issues

If I put the bike in gear then pull the clutch in and push the bike, the clutch feels like it's dragging and it's very hard to push, in Natural it's easy to push.

The bike was parked in a container for 5 years before I got my hands on it and I am wondering whether corrosion could be a factor.

any advise would be gratefully recieved