It could well be the 64-year-old's swansong in the game's oldest major. Former champions are exempt until they are 60 but the R&A created an extra exemption that allows past winners to play for five years if they finish in the top 10. Watson, a five-time Open champion, earned that right by memorably finishing second in the 2009 Open at Turnberry at the age of 59.
This month's championship at Hoylake would have been the final year of that exemption but the R&A's gesture will see him return to the home of golf in 2015 and enjoy another emotional march over the Swilcan Bridge.
"I was hoping they were going to do this - to let me walk across the Swilcan Bridge one last time.
"St Andrews is the place where I want to finish my career . . . unless I can finish in the top 10 and qualify for more Opens."
Meanwhile, Carnoustie, the venue for Watson's first Open triumph in 1975, was last night unveiled as the host of the 2018 championship. Royal Birkdale, the course where Watson won his final Claret Jug in 1983, will stage the 2017 Open.