Danielle O’Toole had a complete-game shutout vs. ASU on Friday and closed out Saturday’s game with a save.

Dominance in the pitcher’s circle isn’t something new for Arizona’s softball program, although it isn’t the constant it used to be.

Before this season, the last time the Wildcats even had a Pac-12 pitcher of the week was in 2012, when Shelby Babcock won the award.

Around that time, Danielle O’Toole began to master her best, well, tool as a pitcher. A tool that’s helped her earn two pitcher-of-the-week distinctions already this season, the latest coming Monday after a stellar weekend against Arizona State.

O’Toole’s fastball can top 67 miles per hour. Then she’ll sneak in her ace in the hole, a 48 mph drop change-up.

“It’s killer,” said UA pitching coach Stacey Iveson. “Or ‘filthy,’ as the girls would say.”

In her first season as a Wildcat — she spent her first two college years starring at San Diego State — O’Toole has the best ERA (1.69) in the Pac-12 and has kept an occasionally sluggish UA lineup in every single game she pitches. She’ll start in the circle Thursday night at 7 p.m., when Arizona takes on Utah at Hillenbrand Stadium.

O’Toole is carrying an 11-5 record to go with that ERA, along with 94 strikeouts in 95 innings pitched.

It all goes back to that change-up, the development of which goes all the way back to a three-year stretch starting at age 14.

For three years, the change-up became a part of O’Toole’s life, her routine. Pitching was ingrained in her mind by her parents.

O’Toole’s mother knows a little something about pitching — the former Diana Moreno pitched at UC-San Diego between 1989-92, and still holds the program record with a 0.91 career ERA.

So every day, O’Toole had an ultimatum — 50 practice throws a day. No excuses.

O’Toole’s father told her, “If you don’t do it every day, you’re going to have your phone taken away,” she recalled. “He’d have my siblings make sure I did it.”

If she couldn’t go outside, O’Toole would wrap one sock inside of another sock, make it into a ball and throw it down the hallway.

“I worked on it for a long time,” she said.

Added Iveson: “That’s what it takes. A lot of repetition. It’s become second nature. To have a great change-up like that, that’s tough to beat.”

Pac-12 opponents are about to learn that firsthand.

O’Toole held Arizona State to one hit during a complete-game shutout on Friday, and closed out Saturday’s game with a save.

Together, O’Toole and freshman Taylor McQuillin have brought a stability to Arizona’s pitching rotation that it hasn’t felt in years. McQuillin (8-3) is fourth in the conference in ERA at 2.65, and as a team the Wildcats are in first place.

“They’ve given us a chance,” said UA coach Mike Candrea.

At many schools, McQuillin would’ve walked onto campus and become the team’s staff ace. In a conference like the Pac-12, that’s a lot of pressure on the shoulders of a first-year player, even one with McQuillin’s pedigree. She was the national Gatorade Player of the Year as a junior and went 55-2 in her last two years at Mission Viejo High School in California.

At Arizona, though, O’Toole is here to carry the load, and she will be for one more year after this.

So far, they’ve complemented each other quite well.

“She goes in when I need it, and I’ll be there when she does,” McQuillin said, “but she usually never does.”

It all circles back to O’Toole’s off-speed killer. All of her pitches are solid, but it’s that change-up that’s helped carry the Wildcats to a 20-9 record to start the season.

“When she’s throwing it well, it’s tough to hit that. It’s a knee-buckler,” Iveson said. “To have a great change-up like that, that’s tough to beat.”

Inside pitch

  • Eva Watson returned to the UA lineup against ASU. The outfielder missed the previous 16 games with a knee injury she suffered during the Mary Nutter Classic in Palm Springs on Feb. 21. Watson went 1 for 8 against the Sun Devils; her .459 batting average is still tops on the team. Candrea said she’s “not quite 100 percent.”