Connacht have announced that flanker Sean O'Brien has been advised to retire from rugby on medical grounds following a concussion injury.

The 26-year-old came through the Connacht Academy having represented Ireland at U18, U19 and U20 level. He was also named captain of the Ireland U20s for the 2014 Junior World Championships.

He made his pro Connacht debut during the 2015/16 Challenge Cup, and came off the bench in the Guinness PRO12 Grand Final that same year. A first senior contract soon followed and in total he has made 60 appearances for his home province.

In a statement, O'Brien said: "I'd like to take this opportunity to thank Connacht Rugby for making a young boy’s dream come true. The memories and friendships made will last a lifetime.

"I’d also like to thank all those in Wegians, Roscrea and Calasanctius who played their part in making it possible, and in particular my Dad Iain who coached me throughout my youth.

"Not everyone gets a fairytale ending but I will never forget just how lucky I was to be a part of this club.

"I am looking forward to cheering in the stands."