Hayne unsure about coach's plans

Jarryd Hayne says it has only taken him two weeks to understand the San Francisco 49ers new playbook, but he joked he still might need to stuff a cheat sheet down his shorts.

The former rugby league star told reporters on Wednesday after furiously studying new coach Chip Kelly's playbook for a fortnight it suddenly clicked with him on the weekend.

Hayne said the first two weeks of pre-season training has concentrated on conditioning and strength work, so he is not sure if Kelly will use him as a running back, special teams, both or in a new position.