1. Rory McIlroy, Northern Ireland -- Showing few ill effects from a rib injury that put him on the sideline for seven weeks early this year, McIlroy finished in a tie for seventh two weeks ago in the WGC-Mexico Championship before passing on the Valspar Championship. In his only other start this year, he lost in a playoff to Graeme Storm of England in the BMW South African Open in January, an event sanctioned jointly by the European Tour and the Sunshine Tour. McIlroy wasn't able to fit the Arnold Palmer Invitational into his international schedule until 2015, often apologizing to Arnie for not being able to make it. He tied for 11th when he finally showed up at Bay Hill two years ago, and then tied for 27th in an up-and-down performance last year. McIlroy, No. 3 in the Official World Golf Ranking, posted 3-over-par 75s in the first and third rounds in 2016, but he shot 67 in the second round and closed with a 65.
2. Rickie Fowler, United States -- Other than missing the cut in the Farmers Insurance Open, Fowler has finished no worse than a tie for 16th (in the WGC-Mexico Championship) in his five starts on the PGA Tour this season. That includes the seventh victory of his pro career in the Honda Classic, a tie for fourth in the Waste Management Phoenix Open and a tie for sixth in the WGC-HSBC Champions, lifting him to ninth in the world and 10th in the FedExCup standings. Fowler is making his sixth appearance in the Arnold Palmer Invitational. His only finish in the top 10 was a tie for third in 2013, when he played the middle rounds in 67-67 but had bookend 73s to wind up five shots behind winner Tiger Woods. A year earlier, he was in the chase and tied for fifth heading to the final round but closed with an ugly 78 to slide into a tie for 30th.
3. Henrik Stenson, Sweden -- Stenson has been a factor in the Arnold Palmer Invitational each of the past four years, finishing no worse than a tie for eighth in that span without lifting the trophy. His best result was solo second two years ago, when he started with 68-66-66 but closed with a 2-under-par 70 and wound up one stroke behind Matt Every, who sank an 18-foot birdie putt on the 18th hole at Bay Hill. Stenson also tied for third last year, tied for fifth in 2014 and tied for eighth the year before that. He is playing in the tournament for the ninth time. The fifth-ranked player in the world withdrew from his first PGA Tour event of the year, the WGC-Mexico Championship, because of a stomach bug two weeks ago, but bounced back with a tie for seventh in the Valspar Championship. In his only other PGA Tour start this season, Stenson tied for second in the WGC-HSBC Champions in China last October.
4. Hideki Matsuyama, Japan -- After a week off following a tie for 25th in the WGC-Mexico Championship in Mexico City, Matsuyama will try to get bounce back from a mini-slump. He missed the cut in the Genesis Open at Riviera, where he closed with a 9-over-par 80. Matsuyama won the WGC-HSBC Champions in China and the Waste Management Phoenix Open in addition to finishing second in the CIMB Classic in Malaysia and the SBS Tournament of Champions in Hawaii earlier this season, showing that his game travels well. Matsuyama is ranked fourth in the world and is one point behind Justin Thomas in the FedExCup standings. He is making his third start in the Arnold Palmer Invitational, and last year he closed with a 4-under-par 67 to tie for sixth, six strokes behind winner Jason Day of Australia. Two years ago, he tied for 21st in his first start at Bay Hill, closing with a 68.
5. Jason Day, Australia -- The defending champion in the Arnold Palmer Invitational got off to a solid start this year after missing three months because of a back injury, tying for 12th in the SBS Tournament of Champions and tying for fourth in the AT&T Pebble Beach Pro-Am. However, he lost his world No. 1 ranking by tying for 64th in the Genesis Open and being sidelined by illness for the WGC-Mexico Championship. Dustin Johnson captured both events to take the top spot in the rankings. Day opened with 66-65 last year to claim the lead at Bay Hill and finished with 70-70 to pull out the victory. Kevin Chappell was one stroke ahead when the Aussie sank a 12-foot birdie putt on the 17th hole, and after Chappell closed with a bogey, Day sank a 4-foot par putt at No. 18 to earn the honor of being the last player to accept the trophy from Arnie. In four previous appearances, his best result was a tie for 17th in 2015.
6. Justin Rose, England -- Even though Rose has played well this year, finishing solo second in the Sony Open in Hawaii and recording ties for fourth in the Farmers Insurance Open and in the Genesis Open, he still has not won on the PGA Tour since the 2015 Zurich Classic of New Orleans. Those results, after he withdrew from the Hero World Challenge in the Bahamas in December, have put him 15th in the FedExCup standings, but he is 13th in the world and looking to climb back into the top 10. One of numerous pros who live near Bay Hill in the Orlando area, Rose will make his 12th appearance in the Arnold Palmer Invitational. His best result solo second in 2013, when he took the lead with an opening 64 and was in the hunt until finishing two shots behind Tiger Woods. He also tied for eighth in 2006, tied for third in 2011 and tied for ninth last year.
7. Brandt Snedeker, United States -- With three top-10 finishes in his past four starts on the PGA Tour, Snedeker's game is rounding into form quite nicely with the Masters only three weeks away. Snedeker tied for ninth in the Farmers Insurance Open, finished solo fourth in the AT&T Pebble Beach Pro-Am and tied for seventh in the WGC-Mexico Championship in his last start, reeling off scores of 68-66-65 after opening with a 4-over-par 75. Snedeker has only one top-10 finish in 10 previous starts in the Arnold Palmer Invitational, tying for eighth in 2014, when a 74 in the third round proved to be costly. However, he has not been totally lost at Bay Hill, with five finishes in the top 25, including a tie for 13th two years ago when a 74 in the second round held him back. If Snedeker could get over what seems to be a trend of one bad round, he could contend again this week.
8. Thomas Pieters, Belgium -- The 6-foot-5 Pieters is off to a strong start this year on the PGA Tour, closing with an 8-under-par 63 to tie for second in the Genesis Open, five strokes behind winner and new world No. 1 Dustin Johnson, and tying for fifth in his last start two weeks ago in the WGC-Mexico Championship. One of the rising young stars of the game at 25, Pieters has three victories on the European Tour in the past two years and showed his mettle when Darren Clarke made him a captain's pick last year for the Ryder Cup at Hazeltine. He posted a 4-1 record, the best among players on both teams, including a 3-and-2 victory over J.B. Holmes in singles, although the Euros went down to defeat. Pieters is making his second start in the Arnold Palmer Invitational. He didn't fare so well last year in his debut, closing with a 78 to finish dead last among the 76 players who made the cut.
9. Charl Schwartzel, South Africa -- After a late start this year because of a right knee injury that hampered him late in 2016, Schwartzel got his game going in the right direction last week when he finished solo sixth in his title defense at the Valspar Championship, playing the weekend in 67-67 on the Copperhead Course at Innisbrook. The 2011 Masters champion moves across Florida this week for the Arnold Palmer Invitational as he tries to ramp things up for Augusta National and the first major of the season in three weeks. Schwartzel is making only his third start at Bay Hill, and his first in six years, as he has yet to fare well in Orlando. He tied for 52nd in 2010 and improved only slightly the following year to a tie for 47th. In eight rounds on the course, he has never broken 70 and is a cumulative 7 over par.
10. Wesley Bryan, United States -- The 26-year-old rookie opened some eyes in his past three starts on the PGA Tour, tying for seventh in the Valspar Championship after tying for fourth in both the Genesis Open and the Honda Classic. Bryan played his past 15 rounds in 23 under par, including an 8-under 63 in the third round the Genesis at Riviera and a 6-under 64 in round one of the Honda at PGA National. This run came after he missed the cut in consecutive starts in the RSM Classic, the Sony Open in Hawaii, the CareerBuilder Challenge and the Farmers Insurance Open. He is making his first start in the Arnold Palmer Invitational, but he is seeing most of these courses for the first time. Bryan showed he could win last year on the Web.com Tour when he captured the Chitimacha Louisiana Open, the El Bosque Mexico Championship and the Digital Ally Open to earn his promotion to the PGA Tour.