NORTON, Mass. -- Phil Mickelson has work to do before next month's U.S. Open at Winged Foot, the site of one of his most bitter major championship disappointments. After a second-round 68 at the Northern Trust on Friday put him firmly outside the cut line and effectively ended his season, he has only one place to do it: the PGA Tour Champions.

"Now that I missed the cut and have two weeks off, essentially, I'm hopefully going to go play the Champions event Monday, Tuesday and Wednesday," Mickelson said.

Mickelson, who turned 50 in June, has not yet played in a PGA Tour Champions event. He will make his debut next week at the Charles Schwab Series at Ozarks National, a Monday-through-Wednesday event in Ridgedale, Missouri.

I'm going to play the Champions event this Monday. I've been playing well and I want to play. I wish I was playing in Chicago next week but excited to play my first Champions event.

— Phil Mickelson (@PhilMickelson) August 21, 2020

By missing the cut at the Northern Trust, Mickelson, who entered the first event of the FedEx Cup playoffs in 67th place in the points standings, will fall outside the top 70 and will not be eligible for next week's BMW Championship at Olympia Fields outside of Chicago. He also won't be eligible for the season-ending Tour Championship, which includes only the top 30 on the points list.

When asked earlier this year whether he would consider playing the PGA Tour Champions, Mickelson said he'd think about it but still believed he could compete on the PGA Tour and wanted to focus on just one.

"I don't want to hurt the Champions Tour in any way," Mickelson said then. "And if not playing the Champions Tour is going to hurt it, I'll play a couple of events. I'll probably play one, two or three events a year because I want to support it, I want it to be successful, I don't want to hurt it or be detrimental in any way to it.

"But I feel like to be successful on a tour, you have to commit entirely to that one tour. So if it's either going to be the PGA Tour or the Champions Tour, I don't see me oscillating back and forth."

Mickelson had an up-and-down year on the PGA Tour. He finished third at the AT&T Pebble Beach Pro-Am in February, then missed two consecutive cuts before golf went on a three-month break because of the coronavirus pandemic.

Since the restart, Mickelson tied for second at the WGC-FedEx St. Jude Invitational, but he also has a missed cut and three finishes outside the top 50.

So he heads off to the Champions Tour trying to get his game in shape for the U.S. Open.

In 2006, Mickelson needed par on the 72nd hole at Winged Foot to win the one major that has escaped him over his career. Instead, he made double bogey to lose by one shot to Geoff Ogilvy.