The 10-year-old had a remarkable career, striking at Group One level on the Flat in the 2016 Irish St Leger and also adding a top-level success over obstacles when winning the 2017 Punchestown Champion Hurdle.
He also twice contested the Melbourne Cup, finishing 22nd in 2016 and 10th a year later.
He appeared to be the verge of adding another notable win to his record in the American Grand National when he fell at the last obstacle on Saturday (Sunday AEDT), with officials at the New Jersey venue later confirming Wicklow Brave had fractured his shoulder and had to be euthanised.
Wicklow Brave won 17 of his 59 races – and while Mullins admits his Irish St Leger victory was his best performance, the trainer pointed to the Punchestown Grade One win as his most memorable verdict.
“I would like to pay tribute to Wicklow Brave, who was a real legend in our yard,” Mullins tweeted.
“A career like his will probably never be replicated, going from bumpers to hurdles, back to the Flat and then chasing.
“His best day was winning the St Leger. However, winning the Punchestown Champion Hurdle with Patrick on board to put us ahead in that memorable trainers’ title battle will be remembered around here for a long time.
“He will be missed by Wicklow Bloodstock’s Nick Peacock, Jason Dear – who rode him every day and looked after his every need – and all at Closutton.”
Jockey Paul Townend teamed up with the gelding on 16 occasions and was aboard when he fell.
“Wicklow Brave was an unbelievable horse, and it looked like we were going to have great day, but it put a real dampener on the trip.
“It is a tight track, and the ground is so quick underneath. The soil on the top was starting to shift a little bit, which wasn’t ideal.
“It is a tight bend but once I got him balanced again, he was starting to open up again. I thought I’d have won – and he is a big, big loss.”