Players Championship 2013 Leaderboard: Players Who Will Plummet in Round 2

With barely a breath of wind and rain-softened greens, TPC Sawgrass was more vulnerable than usual. This filled the leaderboard with low scores, and some by players who will not be able to follow up their hot start.

The lightly accomplished Roberto Castro is one. He tied the course record with a nine-under 63, which also led to him tying the record for the largest 18-hole lead at this event at three strokes. A lead he won't carry into the third round. 

Rory McIlroy and Zach Johnson are tied for second at two-under, and one of these guys made also earned a dubious appearance on this list.

Get familiar with the leaderboard, and then I'll lay out the three guys ready for a second-round free fall.

Position	Player	Score	Total
1	Roberto Castro	63	-9
T2	Rory McIlroy	66	-6
T2	Zach Johnson	66	-6
T4	Tiger Woods	67	-5
T4	Steve Stricker	67	-5
T4	Hunter Mahan	67	-5
T4	Casey Wittenberg	67	-5
T4	Ryan Palmer	67	-5
T4	Webb Simpson	67	-5
T10	Henrik Stenson	68	-4
T10	Padraig Harrington	68	-4

Note: For complete scores, visit PGA.com. All statistics and information are courtesy of PGATour.com.

Round 2 Free-Fallers

Roberto Castro

After turning pro in 2007, Roberto Castro's only top-20 finish on the PGA came last year when with a 16th at the Waste Management in Phoenix.

Playing against what is arguably the deepest event there is, Castro dominated. He hit all but one fairway and all but two greens in regulation. He was sticking it close to the pins too, which is key for him.

Castro has only finished two of his events this season with a positive number in strokes gained-putting, and neither of those were as high as the .990 he put up on Thursday.

So, we've got a player who was putting over his head, and putting it closer to the pin than he can on a consistent basis. He can't keep this up.

And we haven't even talked about the fact that he played in the ideal conditions of the morning, and that was his only tournament round he's played at Sawgrass.

Golf Channel's Kelly Tilghman tweeted how remarkable his round was:

With mostly sunny skies and 10-mph winds expected on Friday, via Weather.com, and Castro teeing off in the afternoon, he is going to face greens that are harder to stick and faster to putt on than he did on Thursday. He will not be able to handle it. 

Round 2 Prediction: 74 

Zach Johnson

Zach Johnson was fantastic on Thursday firing a six-under 66 that included a stretch of six birdies in 10 holes. He hit over 70 percent of his fairways and greens in regulation while turning in a nice 1.66 strokes gained-putting.

He was second here last year, and also eighth in 2005, so obviously has the game to contend here. However, he just hasn't had that game this season. 

Johnson has been one of the biggest disappointments of the season. After finishing sixth on the money list last year, Johnson has played in 11 events this year. He has one top-20 finish, and three missed cuts. 

His top 20 was an 18th...in the first event of the year. 

He had a not terrible 35th at the Masters, but has since posted a 48th at the Heritage and a 65th at the Wells Fargo Championship. 

While I'm not counting him out for the season, I am counting him out for the tournament. He has been in too bad of a slump to have the consistency to go low again on Friday. 

Round 2 Prediction: 73

Padraig Harrington

Padraig Harrington's switch to the belly putter paid off on Thursday. Coming into the tournament, he was at 162nd in strokes gained putting. He finished Thursday at an amazing 4.5 mark. 

Obviously, if he can keep that up, he will be a factor. But, come on? This is just his second tournament with the anchored putter, and last week he finished at minus-3 with it. 

It is no surprise Harrington made the switch in putters. He is always tinkering. Golf Channel's Jason Sobel made that connection with how his round went on Thursday: 

Given the way he's been playing, the inconsistency in his round is not a shock. Harrington does have two top 10s this year, but he also has four missed cuts in his eight PGA events, and he's been cut in his last two. 

Along with his putting woes, Harrington is just 166th in greens in regulation, and with the course getting harder, it is going to eat him up. 

Round 2 Prediction: 75