Farmers Insurance Open 2015: Day 1 Leaderboard Results and Twitter Reaction

The 2015 Farmers Insurance Open will be without golf's biggest draw for the last three rounds. Seven-time tournament champion Tiger Woods was forced to withdraw due to a back injury after 11 holes.

Justin Ray of Golf Channel noted just how much injuries have plagued Woods as of late:

Many golfers who were fortunately fit enough to play at Torrey Pines Golf Course in San Diego were able to score quite well. Nicholas Thompson birdied four of his last six holes to take a one-stroke lead over Michael Thompson and two others after most of Thursday's first round.

First-round play was suspended with most players in the clubhouse due to darkness, in part due to a fog delay that halted golfers earlier on Thursday.

Nicholas Thompson hit 16 of 18 greens in regulation and found the fairway often to set up a stress-free round. Since he is still going for his first-ever win on tour, there is considerable pressure on Thompson to keep up his strong start.

Just one stroke further off the pace are Brooks Koepka and Cameron Tringale at six under par. Koepka continues to build on his form from last week, when he won his maiden PGA Tour event at the Phoenix Open.

Jason Sobel of Golf Channel alluded to the torrid streak Koepka has been on:

Presidents Cup captain Jay Haas mentioned how he likes Koepka's mentality, which should translate to multiple trips to the winner's circle soon enough:

A long birdie putt at the par-three sixth hole on the North Course gave Koepka a boost after he'd cooled off in making the turn at four under.

Koepka's massive driving distance allows for a lot of easier birdie opportunities when his game from tee to green is on—and it has been lately, to say the least.

Golf Digest's Ashley Mayo was pleased to see Koepka and other young Americans have strong starts, though Jordan Spieth faded on his back nine to finish level par:

A cluster of talented players have posted five-under 67s, including Jhonattan Vegas, magnificent putter Freddie Jacobson, ball-striking dynamos in Brendon de Jonge and Chad Campbell and rising American star Chris Kirk.

Ryder Cup stalwart Ian Poulter is teeing it up for the first time this season and is also a part of the group at five under, birdieing his last two holes to join the group three shots off the pace.

Competitive rust was still a factor for Dustin Johnson in his return from a lengthy, self-imposed hiatus from tournament play.

Johnson stands at two over through 17 holes. As some consolation, though, he did have the shot of the day when he holed out for eagle at the par-four No. 4 on the South Course.

"

Dustin Johnson is back (and he just holed an eagle from 160): http://t.co/uGmlT2D6NI

— PGA TOUR (@PGATOUR) February 5, 2015"

Golf Central noted the contrast between two of the most physically gifted golfers ever:

The outlook for Woods looks quite ominous in light of his latest on-course setback. Thursday's withdrawal came less than one round after he'd posted the worst score of his PGA Tour career with a second-round 82 in Phoenix, so Woods has a long way to go to return to the top of golf.

Another superstar who's struggled as of late is Phil Mickelson. Three bogeys in his first seven holes in the first round put Mickelson in a tough spot early. However, support from the home gallery helped Mickelson get back on track.

Lefty rebounded with birdies at Nos. 8 and 9 on the South Course, and he stands at one over through 15.

Momentum is huge in golf, and building early-season confidence can help set the tone for the rest of the year. It's critical for Mickelson and especially Woods to right the ship soon ahead of April's Masters.

That's why Koepka should be considered a big favorite to keep his current roll going. Koepka proved he could compete on a big stage with a tie for fourth at the 2014 U.S. Open, and he's validating the resultant hype around him thus far.