GEELONG'S Sam Blease has retired after just one game in his only season at the Cats.

The 24-year-old, who also played 33 games and kicked 25 goals with Melbourne, has not played since suffering a head knock in the VFL against Essendon on July 25.

After several consultations over the past five weeks, specialists left him with no other option but to avoid playing contact sport again, he revealed on Twitter.

Renowned for his speed and sharp goal sense, Blease was twice nominated for a NAB Rising Star but he never cemented his place in AFL football after being drafted by Melbourne at pick No.17 in the 2008 NAB AFL Draft.

He had setback after setback, breaking his leg while playing kick to kick at Yarra Valley Grammar in 2009, delaying his senior debut until 2011.

He played at the Demons during a turbulent time for the club but remained an upbeat character and made inroads in 2012 when he played 16 games.

An ankle injury made 2013 a battle and he only played two senior games under Paul Roos in 2014.

However he struggled to build the endurance required to exploit the opposition for four quarters and only played as a sub for Geelong after being picked up as a delisted free agent at the end of last season.

Blease told the Cats' website he loved his time at the Cats and was looking forward to progressing in life away from the AFL.

Geelong football manager Steve Hocking thanked Blease for his time with the club.

"Sam was unfortunate this year as he was only able to be selected for 12 games in total across both our teams due to a variety of injuries," Hocking told the club's website.

"However, Sam was able to come into our system and fit in really well and we thank him for his efforts."