GEELONG rookie James Toohey has decided to retire from AFL to focus on completing his university degree.

The 21-year-old was dux of St Kevin's College in Melbourne and has been combining football and study since being put on the Cats' rookie list in 2014.

He played 13 VFL games in 2014 and was a popular figure during his short stint with Geelong.

Toohey told family, medical and personal reasons played a part in his decision.

"It's an extremely difficult decision, but one that is the best thing for my health and my family," Toohey said.

"I would like to thank the club for the opportunity, and for all the support they have given me and my family. I am unbelievably grateful for the experience and just wish the best for all my teammates and the club."

Geelong football manager Steve Hocking said Toohey made a positive impact during his time at the club.

"We are happy for James that he has made this decision and have no doubt he will do well in his studies. He is always welcome at the club and we wish James and his family the best in the future."

The Cats also lost Brad Hartman from their list a fortnight ago after he decided to retire .