The USF softball team will take its seven-game winning streak and No. 22 national ranking into arguably the toughest tournament of the season today when the Bulls begin the Worth Wildcat Invitational in Arizona.

The Bulls (15-2) moved into the top-25 for the first time this season after winning all five games last weekend and claiming the USF Best Western title. And though the team will face a couple of the nation’s premier programs this weekend, the Bulls’ confidence level remains high.

“Really, our approach isn’t going to change,” associate head coach Stacey Heintz said. “We’re going to take it one game at a time, try to get the first one and work from there and see how it ends up.

“But we’re going in to try to win the tournament and to see where we stand.”

USF will get a good indication of where it stands nationally, especially on Saturday when it faces No. 2 Arizona and No. 7 Stanford, two perennial national- title contenders from the Pac-10.

“These teams will definitely be the hardest ones we’ve faced,” senior pitcher Leigh Ann Ellis said. “It’s going to be the most challenging (tournament so far this season).”

The Bulls open the tournament today with games against Oklahoma State and Boston University. USF wraps up the tournament with a game on Sunday against an undetermined opponent.

Though Heintz said Tuesday she had not made a decision yet on the rotation for the weekend, it wouldn’t be a surprise to see Ellis take the mound against either the Wildcats or the Cardinals.

In fact, Ellis pitched well last season when Arizona came to Tampa.

She allowed just four hits and two earned runs in a 3-1 loss last February in the USF-Louisville Slugger Tournament.

Neither team’s head coach will be on hand for the USF-Arizona game.

Arizona coach Mike Candrea, the U.S. national team head coach, took the entire year off from his program to focus on the 2004 Olympics, while USF coach Ken Eriksen, an assistant with the U.S. team, will also be away from his club.

The Bulls may also be without preseason all-Conference USA selection Kattrina Dowd.

The sophomore second baseman missed all five games last weekend with a herniated disc in her back, and Heintz said Tuesday she was unsure if Dowd would be in the lineup this weekend. Freshman Alycia LePage filled in for Dowd in the field, while the Bulls tweaked the top of the lineup to make up for the loss of their leadoff hitter.

Heintz said she would do the same this weekend, possibly letting LePage bat second behind senior Shelly Riker, or even moving sophomore Christi Chapman up into the No. 2 spot.

“We’re just looking for something to click, and once we get something rolling, we’re just going to go with it,” Heintz said.