5 groups we can't wait to watch at the U.S. Open

The 118th U.S. Open tees off at Shinnecock Hills in Southampton, N.Y., on June 14, where Brooks Koepka returns to defend his title.

Tee times have been released for the first two rounds and there are some exceptional groupings we'll all be keeping a close eye on. 

Here are the five groupings that really jumped off the tee sheet.

RELATED: U.S. Open tee times, TV schedule | Field list | Live stream links

5. Bubba Watson, Jason Day, Brooks Koepka

Tee times: 7:40 a.m., 1st tee, Rd. 1; 1:25 p.m., 10th tee, Rd. 2
Reason to watch: This group features three major champions. All have been playing well in the 2017-18 PGA Tour season. Watson is a two-time winner this year, having won the LA Open and the WGC-Match Play Championship. Day has also won twice -- Torrey Pines and Wells Fargo. Koepka, meanwhile, missed time at the start of the year due to injury, but he's been heating up lately. That's a good sign as he prepares to defend his first major championship after emerging at Erin Hills one year ago. This threesome is loaded with big hitters that will be fun to watch at Shinnecock. While the length will no doubt be impressive, their respective short games will need to be sharp. 

4. Sergio Garcia, Jon Rahm, Rafa Cabrera Bello

Tee times: 1:14 p.m., 1st tee, Rd. 1; 7:29 a.m., 10th tee, Rd. 2
Reason to watch: If you're a fan of the Ryder Cup -- and, come on, who isn't? -- you're going to want to follow this trio of Spaniards. All three will likely be on the European Ryder Cup team in Paris. First, there's Garcia. He won the 2017 Masters to claim his first major and he's been on the first page of major leaderboards for years. Then there's Rahm, the young gun in the group, who finished fourth at the Masters this year. He's made an incredible rise in the world rankings since turning pro and has established himself as a threat any time he tees it up. The one worry for Rahm could be controlling his emotions at Shinnecock. That rough is going to drive a lot of players mad. Cabrera Bello, a veteran of the 2016 Ryder Cup at Hazeltine, notched his lone top-10 major finish at the 2017 Open Championship -- a T4.  

3. Ernie Els, Steve Stricker, Jim Furyk

Tee times: 1:36 p.m., 10th tee, Rd. 1; 7:51 a.m., 1st tee, Rd. 2
Reason to watch: Respect your elders, kids. All three of these players are among the most well-respected on the PGA Tour. All have been, or will be, captains of team competitions as well -- Stricker (2017) and Els (2019) in the Presidents Cup; and Furyk the current Ryder Cup USA Captain. Els and Furyk are both past U.S. Open champions. Stricker, though he hasn't won a major, has achieved just about everything else in the game. A win by any one of these three players at Shinnecock would make them the oldest U.S. Open winner in history. But don't be shocked if they gave it a run. They all still have plenty of game.

2. Rory McIlroy, Jordan Spieth, Phil Mickelson

Tee times: 8:02 a.m., 10th tee, Rd. 1; 1:47 p.m., 1st tee, Rd. 2
Reason to watch: These are the only three active players who are all one major away from completing a career grand slam. Out of the trio, Mickelson is the only one who could do so at Shinnecock -- a place where he finished runner-up in the 2004 U.S. Open, one of his record six runner-up showings in this championship. Think that's some motivation? McIlroy hasn't won a major since the 2014 PGA Championship and is hungry to add more to his resume. Spieth hasn't played his best golf in 2018, but will surely be hoping to find some putting magic on the difficult Shinny greens. If Spieth gets himself in the mix, look out. He thrives in the majors.

1. Justin Thomas, Dustin Johnson, Tiger Woods

Tee times: 1:47 p.m., 1st tee, Rd. 1; 8:02 a.m., 10th tee, Rd. 2
Reason to watch: Do we really need a reason with this trio?! OK -- how about this: world No. 1, world No. 2 and 14-time major champion Tiger Woods, playing in his first U.S. Open -- healthily, we might add -- since 2015 and just his second since 2013. Those are all pretty good reasons. As is usual, all eyes will be on Woods. What kind of game will he bring to the sternest of all major tests? He's had flashes of brilliance this season when not a whole lot was expected of him, but hasn't yet strung together four great rounds in a tournament. Thomas and Johnson have continued to do their thing, which is being present on page-one of leaderboards regularly. Don't expect that to change next week. The big question, as it often is, will be: What will we get from Tiger? We don't think he'll have an issue making the cut, but is his first major win since the 2008 U.S. Open in the cards? Can you imagine?