The birth of his and wife Amy's third child was life-threatening both for her and the baby, Mickelson said.
'I didn't really get into it too much, but Amy had a very dangerous delivery with the birth of Evan,' Mickelson said. 'He had a very difficult delivery, too.
'He didn't breathe for seven minutes, and had the emergency nurses not been there with the equipment ready, he might have had some severe brain damage or other circumstances.'
It was also touch-and-go for his wife during the birth last March.
'We were two or three minutes away from losing her,' Mickelson said.
He explained that the radiologist was nearby when the problem was discovered, so was able to quickly perform an emergency procedure.
'They had to stop a six-inch tear in a major artery, or I would have been without my wife,' Mickelson said.
'I am so excited about 2004 because my wife's health is 100 percent, my son's health is 100 percent, and my two daughters are doing great,' he said.
The 33-year-old Mickelson also believes his game is going to be 100 percent this year after his worst season on the PGA Tour.
He failed to win last year - with his most recent victory coming in the 2002 Hope Classic - and didn't make the Tour Championship for the first time. He also fell to 38th on the 2003 earnings list.
The left-hander, still looking for his first win in a major, had not finished lower than 28th previously in his 11-year career.
He's ready to play his way back toward the top.
'I've had a wonderful time off the last couple of months and am really looking forward to the year,' Mickelson said Tuesday in the press tent on the eve of the 45th Hope Classic. 'I feel it's going to be a great year.
'I've been chipping and putting for two months. I want to get rid of the bad swing mechanics from 2003. I was pathetic last year from 130 yards in; before that, I was one of the best.'
He said he was aware that some have questioned his heart and motivation.
'I think that I still have the same heart, the same desire, the same motivation that has led to 21 tour wins, and I expect it to carry through this year, too,' he said.
This is the first time the Hope tournament has been played since the death of its namesake last summer.
'He really took the responsibility to bring golf up,' Mickelson said of the late comedian. 'By associating his name with the tournament, he helped bring the game to the masses.'
Mickelson is one of the favorites in the five-day, 90-hole tournament that is played on four courses.
Most of the pros are teamed in rotation with celebrity and amateur partners for the first four days, then the pros go it alone on Sunday.
The tour players can opt out of playing with amateurs, and Mickelson has gone that route in recent years, saying he can focus better when he plays with other pros.
He will be competing with a field that includes defending champion Mike Weir, who began his breakout year with a Hope victory. Weir went on to win the Masters and the Nissan Open.
'I didn't know I was going to play as well as I did, but I did and now I know I can,' Weir said of the year that ended with him fifth on the earnings list. 'Now it's a matter of just keep working to improve my game.'
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