You've never seen the energy in a room change the way it did Thursday afternoon in the press tent at the Northern Trust Open. Phil Mickelson had just shot a sterling eight-under-par 63 when word came down that Tiger Woods was returning to golf at next week's Accenture Match Play Championship. BlackBerries buzzed and emails hurtled across cyberspace. Writers and editors huddled on the phone. Flights were re-routed to the Arizona desert and hotel rooms were booked. In an instant, Mickelson's round was rendered a side note, left in the wake of a golfer who has yet to hit a shot in anger in 2009.

Woods is not playing at Riviera, but his presence will be felt in the second round and beyond. I will be watching Mickelson in particular to see how he responds to shooting 63 and to the news that Woods will be back on the prowl shortly. In a non-descript season to date, a Mickelson victory at Riviera would be the best way for the PGA Tour to get even more juice heading into the Match Play. Let's see if Mickelson can stack a 65 on top of his 63 and put some distance between himself and the field. I watched Mickelson hit consecutive irons to 2 feet on holes No. 3 and 4 on Thursday. Whatever was ailing him for three straight tournaments - namely wild misses to the right - wasn't on Thursday. He looks like a man on the way back.

I'll also be watching to see if Vincent Johnson, playing on the Charlie Sifford Exemption, can make the cut following his opening-round, one-under 70. The 22-year-old Johnson positively bombs it off the tee and he outplayed 17-year-old Ryo Ishikawa, whose PGA Tour debut netted a two-over 73.

Two more to keep an eye on: Scott McCarron, who played his college golf at nearby UCLA and shot 64 on Thursday. He knows this golf course as well as anyone. Also, Fred Couples, who could play Riviera blindfolded. He carded a smooth 67 to stay within shouting distance of Mickelson.

But the birdies and bogeys at Riviera will pale in comparison to the countown to Woods's opening tee shot Wednesday in the desert. The entire vibe surrounding the PGA Tour changed. Next week, the season begins in earnest.