Phil Mickelson on his game: Mental focus an issue

(CBS News) Golf great Phil Mickelson has won four Grand Slam titles, and was just inducted into the World Golf Hall of Fame. But his game this year hasn't been what it once was, he admitted on Thursday on "CBS This Morning."

"I haven't played my best," he said.

Mickelson failed to make the cut at the British Open last week and also at the Greenbrier Classic in West Virginia back in early July.

Mickelson said he's spent a lot of time trying to figure out what the issue may be and said he's identified "a couple of things." He said, "One of the biggest areas...is that mentally I haven't been focusing as fine as I need to. I've been letting where I don't want the ball to go kind of creep in, in my head, as opposed to where I want it to go."

He continued, "I've been a little bit lethargic those last two months. We've got some big tournaments coming up. In fact, the next nine weeks I'm playing seven of them. This is an important stretch to finish the year off right, and I've been working hard to turn it around. It's been a fun challenge."

Mickelson said sometimes it takes a few events to find out what's going on with his game. "If I look back over the last couple of months, it's easier to identify where I've been going off, and I haven't played with the same purpose, whether it's approach heading into the golf tournament or whether it's on each individual shot. That's what I'm going to try to focus on these coming months to get this back on track."

In addition to discussing how he's getting help from legendary golf instructor Butch Harmon, Mickelson also talked about the importance of his competitors and an initiative he and his wife, Amy, founded called the Mickelson Exxon Mobil Teachers Academy, which helps teachers understand math and science. For all that and more, watch the video in the player above.