Phil Mickelson left an eventful week at Torrey Pines and is now focused on defending his title at the Northern Trust Open.

The world number two began his 2010 campaign at the Farmers Insurance Open. It was his first week back on the PGA Tour since back to back victories in the Tour Championship and WGC-HSBC Champions and he opened it deflecting questions about the scandal surrounding arch rival Tiger Woods and discussing the treatments his wife and mother are undergoing for breast cancer.

By the end of the second round on Friday he had been accused of cheating by fellow professional Scott McCarron for his decision to play with a pre-1990 Ping wedge that features non-conforming grooves, but is approved for PGA Tour use due to an early 1990s legal settlement between the game's governing bodies and the club manufacturer.

On Saturday, having criticised the rule that allowed him to put the club in play but defended his right to use it, Mickelson announced that he was considering what course of action to follow following what he called McCarron's "slanderous" comments.

All the time he stayed within touching distance of the top of the leaderboard, but yesterday's final round saw that challenge fade after bogeys at his first three holes.

And the American is determined to put technical issues with his swing right with coach Butch Harmon ahead of this Thursday's first round at Riviera.

"A lot of it was just timing," Mickelson said of his final round 73, which left him in 19th place at Torrey Pines. "A lot of it was just out of whack, a little too long and a little lazy through the ball and didn't quite have the speed and momentum going toward the target.

"I got off to a terrible start, and then throughout the round didn't get much out of it. But the good thing is that I've got a direction of what I'm working on.

"I felt like I hit some good shots coming down the stretch. The last 13, 14 holes I actually hit a lot of good shots. I'm excited about next week because my game is feeling not as rusty as it looks, and I've had some success up at LA."

Mickelson added: "I'm excited to be back playing golf. I missed being out and playing competitively.

"I've had 10 weeks off, and I'm excited about getting the year started again. I love starting in San Diego. It's one of my favourite tournaments, and I felt like I was ready.

"I didn't get the performance I wanted, but next week in LA, I think that I should be able to get it turned around."

The world number two also found time to praise PGA Tour rookie Rickie Fowler, one his final-round playing partners at Torrey Pines, who finished tied for fifth.

"What a great asset to the Tour this guy is," Mickelson said of 21-year-old Fowler, who will also play at Riviera this week.

"He's a great player, really a fun guy to be around, and I think he's going to really enhance the game of golf.

"He's long, he's got a great short game, he's got great control of his irons. I just think overall he's a very solid player. I think he's going to have a great year."