"It was definitely a good outing for me; definitely something I felt like I needed," Thatcher said. "I'm glad it happened."
Thatcher, 32, missed 37 games from Aug. 3 to Sept. 12 while rehabbing a sprained left ankle and feels he's now "getting that little bit of sharpness back."
"I feel like I'm really close to being the player I need to be and being dominant again," he added.
Thatcher had a 2.63 ERA, a 1.08 WHIP and an 8.33 strikeout-to-walk ratio in 37 appearances on July 5, when the Angels sent outfielder Zach Borenstein and reliever Joey Krehbiel to Arizona in exchange for Thatcher and speedy outfielder Tony Campana.
In 15 games since joining the Angels, though, Thatcher has a 6.00 ERA, a 2.00 WHIP and a 1.00 strikeout-to-walk ratio, with left-handed hitters sporting a .368/.435/.474 slash line in 23 plate appearances against him.
If Matt Shoemaker (strained left oblique) is healthy, the Angels could have 11 pitchers solidified for the postseason roster: Shoemaker, Jered Weaver, C.J. Wilson, Hector Santiago, Huston Street, Joe Smith, Kevin Jepsen, Jason Grilli, Fernando Salas, Mike Morin and Cory Rasmus.
Thatcher could make the roster if the Angels go with a 12-man pitching staff, which is uncommon for a five-game series but may make sense for a team that has several rotation questions.
Performances like Saturday's help make his case.
"I can't worry about that," he said. "As soon as you start worrying about that kind of stuff, you lose focus on what you need to do. I know what I can do. Whatever they decide is best for the team moving forward is good by me."
Alden Gonzalez is a reporter for MLB.com. Read his blog, Gonzo and "The Show", and follow him on Twitter @Alden_Gonzalez. This story was not subject to the approval of Major League Baseball or its clubs.