"I think I was a little anxious today," Maurer said following his start. "[I] threw a few too many [pitches] in the bullpen before I went out there. I was fired up."
Maurer was fired up and excited for his first start in any game since 2014 when he was still in Seattle, trying to stick with the Mariners. He spent last season as a late-inning reliever for the Padres.
Maurer allowed five runs on two hits with three walks against the D-backs, during a stint that lasted 1 1/3 innings before he reached his pitch limit (41 pitches, 19 of which were strikes).
"Today definitely felt like I was getting in that starter role … getting ready for the game in a different way," Maurer said.
Maurer breezed through the first inning, getting two strikeouts as he was able to mix his fastball and slider with success. But he struggled in the second inning, allowing a two-run home run to Peter O'Brien and three walks.
The home run to O'Brien came on an 0-2 pitch.
"I thought [command] was OK. I kept the ball down for the most part," Maurer said. "[I] maybe yanked a couple pitches, but overall I felt my command was pretty good."
Maurer threw only one curveball, and landed it for a strike in the second inning. It's a pitch he wants to use more and one the Padres would like to see more of.
"Everything felt pretty good today, to be honest. Ran out of gas there a little bit, but that's expected early on. … I'll take it in stride," he said.
San Diego manager Andy Green was pleased with the way Maurer looked.
"Honestly, I thought his stuff was sharp. I thought it was really sharp, especially early on," Green said. "He was commanding his fastball down in the zone. His slider was finishing at-bats. I was actually encouraged by his stuff."
Now it's up to Maurer to continue to build his stamina and increase his innings as he shifts back to starting.
"It's building stamina, he needs to do that," Green said. "It's part of being out there and getting extended. His stuff plays, there's no doubt about it. The real question is whether we can keep him in shape to withstand the starter's grind, and if he can, he's going to have good enough stuff to compete there."
• Pitchers Kevin Quackenbush and Fernando Rodney, who haven't appeared in games yet due to hamstring strains, have progressed to the point where they will pitch in a game on Friday against the White Sox. Both pitchers threw batting practice Tuesday.
"I thought Fernando Rodney was borderline electric," Green said.
Reliever Matt Thornton, who signed a Minor League deal with the team on March 3, will also appear in that game Friday.