The New Zealander spent five seasons as professional at Cambusdoon before taking charge of his country's under-19 side and then becoming coach of Auckland Aces, a post he still holds.
Horne may have been away for six years but McElnea insists the work he started a decade ago is now bearing fruit. Saturday's 61-run win over Dumfries confirmed Ayr's first Union title since 1996, capping a fine season for the young Alloway team.
Their success is all the more remarkable in that it was sealed almost a year to the day since they came within one game of losing their top-flight status.
"Everyone at the club is delighted," said McElnea. "A lot of hard work has gone into this and there is no doubt that much of the credit is due to Matt Horne. It is very much his legacy that we have a young team who have proved themselves capable. Most of the guys who have played throughout the season were juniors at the club when Matt was here.
"He was one of these special professionals who was more than just a guy who went out and got runs and wickets for the first XI - although his record there was really impressive.
"But even more important was the influence he had on all the juniors. He worked tirelessly at every level at the club and the way he taught us to play has provided the foundation of what we do every time we go on the park.
"Myself and my brother [Scott], Neil Smith, Callum Leck, Shujaa Khan, Elliot Speirs, Neil Logan, Ross Mitchell and Richard Borland are all products of the time when Matt was at the club. It is a fantastic feeling to be Western Union champions, especially when you remember we played Stirling on the final day of last season in a game we had to win to stay up."
While the local players will rightly receive their share of the plaudits, the contribution of Sikander Raza, Ayr's Zimbabwean professional, should not be overlooked.
Despite heading off on international duty six weeks ago, Raza ended the season as the leading run scorer in the Union as well as one of the top-10 wicket-takers.
His replacement, Steve Liburd, also made some important contributions, including taking 3-52 in Saturday's typically hard-fought win at Nunholm.
Scott McElnea more than matched that effort with 3-25 as Ayr pegged back Dumfries, who had looked on course to chase down their 246 target.
Earlier, Shujaa Khan, the youngest of Ayr's talented crop, had demonstrated the most maturity with a composed innings of 49 after skipper McElnea had set the tone with 36, his brother adding the finishing touches with a hard-hitting 39.
Ayr will now attempt to be the first side from the west to win the grand final when they face Eastern Premier champions Aberdeenshire on Saturday.