Mickelson tunes up at the San Diego Open in Torrey Pines
World number two Phil Mickelson begins his US Tour campaign at the San Diego Open starting on Thursday insisting golf needs Tiger Woods to return soon.
Woods is taking an indefinite break because of his much-publicised personal problems but Mickelson said: "It's important for him to come back.
"He's got a lot more important things going on in his life but the game of golf needs him to come back."
Luke Donald, Ernie Els and Justin Rose also feature at Torrey Pines this week.
Mickelson ended 2009 in superb form, capturing the PGA Tour's season-ending Tour Championship in September and the WGC-HSBC Champions in China in November, both of which featured Woods.
We care deeply about how this turns out
"First of all, I feel ready but second, at the end of last year, I felt like things were starting to really come together," said the 39-year-old left-hander.
"Taking some weaknesses and turning them into that strength gives me the confidence or the belief that this could be an exceptional year."
Asked about the effect that the absence of Woods could have on his chances of success he said: "Nobody will be able to fill the shoes that are voided right now. My whole career I've been trying to get to number one, I just haven't had much success.
"But this year, whether or not Tiger is in the field, I believe is an opportunity for me to compete in majors."
Mickelson was forced to take a break from golf himself last year as both his wife Amy and his mother were treated for breast cancer.
Popular perception for a long time was that he and Woods did not get on but the left-hander said: "Amy and I are good friends with both Tiger and (his wife) Elin and we care deeply about how this turns out.
"But I'm going to choose not to talk about it publicly any more ... we're friends and we have a personal relationship. I feel like it's a violation of our trust and our relationship."
Some observers have suggested Mickelson has an even greater responsibility to provide star quality while Woods is out of the picture but he said: "I haven't thought about it like that.
"I'm just excited to play golf. I'm excited to get back into competition and be a part of this.
"I was putting well at the end of last year but in the last three years I've taken what has always been a weakness in my game - driving - and I feel like I've turned it into a real weapon."