The Olympia Fields Country Club continues to beat up on the best golfers in the world at the BMW Championship.

It’s certainly been tough on the three Cal golfers playing in suburban Chicago:

— Max Homa, who won the NCAA title while at Cal in 2013, is tied for 39th place, seven strokes off the lead after Friday’s second round.

— Byeong Hun An, who played one season at Cal in 2011, is tied for 45th, eight strokes back.

— And second-year pro Collin Morikawa, who entered this week ranked No. 5 in the FedEx Cup standings with two weeks left in the series, faces a drop in those rankings unless he turns things around this weekend. He moved up just two spots from Thursday to a tie for 58th place and trails by 10 strokes.

Saturday should be exciting for Morikawa, thanks to his playing partner, some guy from Stanford:

Collin Morikawa will be paired Saturday morning with Tiger Woods

The field of 69 golfers is not cut after two rounds, so all three will play through Sunday. Rory McIlroy and Patrick Cantlay share the lead at 1-under-par 139. They are the only two golfers shooting under par through 36 holes.

Dustin Johnson, who moved into the FedEx Cup lead after shooting 30 under par last week to win The Northern Trust, is tied for third at even-par 140. He shares that spot with first-round leader Hideki Matsuyama.

"Last week was fun, too," Johnson said. "But this week is more of a grind, that's for sure. Every single hole out here is difficult. You've got to really be focused on every shot that you hit."

Defending champion Justin Thomas and Daniel Berger, who began the week at No. 2 and 4, respectively, in the FedEx Cup rankings, are tied for 45th at Olympia Fields.

Tiger Woods is at plus-8 and tied for 55th place after shooting a 75 on Friday. 

McIlroy acknowledged the course has been more than challenging and has taken on the feel of a U.S Open.

"I think the test is what's helped me focus and concentrate because if you lose focus out there for one second ... just one lapse in concentration can really cost you around here," McIlroy said.

"I think one of the big keys this week is just not making big numbers. If you hit it out of position, get it back in position, make sure that your worse score is bogey and move on. Honestly, bogeys aren't that bad out here."

Homa is 68th in the FedEx Cup standings and out of contention to climb into the top-30, necessary to advance to next week’s Tour Championship, final leg of the FedEx Cup chase.

Homa shot a 72 on Friday in a round that included three birdies, three bogeys and a double-bogey on the fifth hole for the second straight day.

An had a 74 in the second round after posting five bogeys and just one birdie.

Morikawa made a jump from shooting a 76 on Thursday to a 73 a day later. His round included five bogeys and two birdies.

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Follow Jeff Faraudo of Cal Sports Report on Twitter: @jefffaraudo

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