Jonjo O'Neill's stable jockey Liam Cooper has announced his retirement after suffering recurrent concussions and admitting: "One more heavy fall and I could have been history."
The decision to retire was taken after Cooper was warned by a top London specialist that one more fall could have brought tragic consequences.
The 25-year-old suffered a crashing fall from hurdler Feel The Pride at Sandown on April 24th, a tumble that took him several weeks to recover from.
Despite the arrival of champion jockey Tony McCoy at Jackdaws Castle just days after his spill, Cooper was planning to ride this season as second jockey for O'Neill.
He said: "The decision was basically made for me. I went to see a specialist in London and though he said that from his point of view I could carry on, it came with the understanding that one fall and another concussion might mean irrevocable damage.
"He said that though nothing could be predicted, it would be a wise decision to stop race riding."
The Cumbrian-born rider, whose biggest moment came when Intersky Falcon landed the Christmas Hurdle for the second time on Boxing Day last year, has been troubled by a series of concussions in recent seasons and he sought further medical advice when he found himself taking longer to recover.
"It used to take 24 or 48 hours to overcome a concussion, but they have been taking longer the more I have had. I was worried when this one took a lot longer and when a month went by and I still wasn't feeling right, I was naturally concerned," he said.
"When the specialist gave me his advice, it came as a shock - it's hard to take, but you have to look at the longer term."
Cooper built up a great association with crack hurdler Intersky Falcon and staying chaser Clan Royal among others at O'Neill's yard, landing the John James McManus Memorial Hurdle at Tipperary, the Christmas Hurdle at Kempton and Newcastle's Fighting Fifth Hurdle aboard the former.
Instrumental in giving O'Neill his third consecutive century of winners, having taken just one outside ride last season, Cooper rode Clan Royal to a success in November's Tote Becher Chase before finishing a gallant runner-up to Amberleigh House in the Grand National, despite losing his whip five out.
"Jonjo has been very supportive and I was lucky enough to ride some great horses," said Cooper. "He has been supportive of me throughout my career and especially in the last few days since making this decision. I have nothing but admiration for him.
"I am going to take stock of everything and see what comes to me. There is plenty of work to do here for Jonjo and he has said there will always be a position here for me, so naturally I am very thankful for that."
O'Neill said he was "saddened" by Cooper's premature retirement and praised his work ethic.
"Liam has been a very big cog in the wheel here for a few years and it is a real blow to lose him, especially since he is not going out on his own terms," he said.
"He was told by the specialist that another fall would not be too clever and you have to respect that. It's a real shame for the lad and we are all saddened by it.
"He's a quiet lad and would never be one to blow his own trumpet, but not only is he a tireless worker, he also gives a horse great confidence. He has given the yard some great moments and it is a great pity that he's had to pack up.
"He'll be looked after. Whatever he wants to do, we will back him 110 per cent."