Lorena Ochoa, the first Mexican to win on the LPGA Tour, struggled early at last year's MasterCard Classic but rallied to finish fifth.
'I think last year in this tournament I learned more than I did in three years on tour,' Ochoa said.
The former University of Arizona star won the Wegmans Rochester LPGA in June and is one of only two players to finish in the top five at both LPGA tournaments this season. The Guadalajara golfer won three times in her first three full seasons on the tour.
Sorenstam has won three of her last four season openers, and she will be making her second straight season debut at this tournament.
'This is a great start to the season. I've got good memories,' said Sorenstam, who enjoyed a three-stroke victory over Karrie Webb last year. 'I'm happy to be back here and I don't feel any extra pressure.'
The title in Mexico is one of 10 the Swede will defend this year. She has 21 victories worldwide and three major championships the past two years.
Joo Mi Kim won the season-opening SBS Open at Oahu, Hawaii, and Meena Lee won a week later at Kapolei, Hawaii. Lee will be looking to make it two straight at the MasterCard Classic.
Sorenstam doesn't dwell on her intimidating presence.
'I really don't walk around thinking, 'What are the other players thinking?'' she said. 'I try to mind my own business, do what I've got to do. I set some high and really lofty goals, but that's what keeps me going.'
In February, the first women's rankings put Sorenstam at No. 1.
'I think for the future it's going to give us good measurements on the performance of everybody around the world,' Sorenstam said. 'It's really tough to compare the money list, especially with the purses being different.'
The 35-year-old Swede is chasing a record many thought out of reach: 88 career LPGA victories by Kathy Whitworth. Sorenstam has 66.
'I've always felt like that was so difficult to achieve,' she said. 'I mean 88 wins, if you think about it for a minute, it's just amazing. But I'm a lot further than I thought I would be.'
Last year's MasterCard Classic marked the LPGA's first Mexican event since the Bing Crosby International, which was played in 1974 and 1975 in Guadalajara.
There was another tour stop in Mexico a year ago, with Carin Koch winning the Corona Morelia Championship in April, an event Sorenstam skipped. The LPGA will head back to Morelia in October.
Because of the hilly terrain Bosque Real Country Club and long distances between holes, players and caddies will be allowed to use carts for the first time in tour history.
The tournament will be played at an altitude of 7,400 feet. That will afford sweeping, though smog-shrouded, views of western Mexico City. But it also promises to send balls soaring. Sorenstam said shots will carry 15 percent farther, making consistency with irons more important.
'It's a course that's a lot hillier than we play throughout the year. It's also a course where the elevation makes a big difference,' she said. 'So you have a few more things to really think about.'