Jordan Spieth US Open 2015
American Jordan Spieth is now the odds-on favorite to win the British Open next week in Scotland. Getty Images

The modern Grand Slam might not be so farfetched an idea for Jordan Spieth, at least according to odds makers.

Due to No. 1 Rory McIlory’s ruptured ankle, the American Spieth is now considered the favorite to win next week’s British Open at St. Andrew’s in Scotland. After claiming the Masters and the U.S. Open, Spieth’s chances are now at 5/1 to snag the third slam of his career and of the year.

McIlory, who was originally the favorite at 9/2 but has since fallen to 9/1, suffered a ruptured anterior talofibular ligament, or ATFL, in his left ankle while playing soccer with friends on Saturday. The world learned of the injury via the 26-year-old’s Instagram account.

The defending British champ included a caption with the photo of him standing with crutches and a walking boot, saying: "Continuing to assess extent of injury and treatment plan day by day. Rehab already started. ... Working hard to get back as soon as I can."

As of now it’s unclear if McIlroy will play at the Open, but he’s already pulled out of the Scottish Open, a tournament many players use to tune up for St. Andrew’s infamous winds and hilly fairways and greens.

Fine tuning his game and seemingly getting stronger with each tournament, Spieth finished 5-under at the U.S. late last month while a huge majority of the field struggled with the treacherous Chambers Bay course. The 21-year-old Texas native was one of only eight contenders to shoot under par by the tournament’s end.

But a host of veterans and former British champions stand in McIlory’s way. American Dustin Johnson, who wound up tied for second at the U.S. after missing a very short putt that could’ve beaten Spieth, is behind McIlory at 12/1 odds. Next up is England’s Justin Rose at 16/1, and Australia’s Adam Scott at 18/1.

And Tiger Woods, despite his very poor play of late, is actually listed at 22/1, ahead of Phil Mickelson at 25/1. Woods flamed out to miss the cut at Chambers Bay, arguably the worst showing at any major in his career, but has slightly recovered with 7-under final score for 32nd place at the Greenbrier Classic over the weekend.

The first round of the tournament begins Thursday, July 16.

Odds to Win British Open

Jordan Spieth 5/1

Rory McIlory 9/1

Dustin Johnson 12/1

Justin Rose 16/1

Adam Scott 18/1

Henrik Stenson 20/1

Louis Oosthuizen 20/1

Tiger Woods 22/1

Jason Day 25/1

Martin Kaymer 25/1

Phil Mickelson 25/1

Rickie Fowler 25/1

Sergio Garcia 25/1

Bubba Watson 28/1

Paul Casey 28/1

Hideki Matsuyama 33/1

Branden Grace 35/1

Patrick Reed 40/1

Shane Lowry 40/1

The full list can be viewed at Bovada.lv.