"It will hopefully be a short stint for Matt down there," said Angels Manager Mike Scioscia, who added that he told Shoemaker to be ready "for when you go back in our rotation, which will happen."
Shoemaker has a 2.81 earned-run average in three starts, but he lasted only five innings on Saturday. The Angels used three of their top relievers -- Joe Smith, Ernesto Frieri and Fernando Salas -- for two innings apiece, and they needed a fresh arm in case of a short start by Garrett Richards on Sunday.
"If I went another inning or two, if the game didn't go extras ... everything is part of it," Shoemaker said. "This game is an awesome and crazy game."
If LeBlanc is not needed in relief Sunday or Monday, the Angels figure to start him in Shoemaker's place Thursday against the Seattle Mariners. LeBlanc is 5-1 with a 3.69 earned-run average at Salt Lake this season, and he has given up two runs in his past 20 innings.
LeBlanc, 29, has started 68 games in the majors. He opened last season in the Miami Marlins' rotation, but he went 0-5 with a 6.11 ERA in seven starts and was demoted to the bullpen in May, claimed on waivers by the Houston Astros in June and out of the majors for the year in August. The Angels signed him to a minor-league contract last November.
LeBlanc was notified of his call-up late Saturday night and caught a 7:10 a.m. flight from Salt Lake City in order to make the 12:35 p.m. game in Anaheim.
"It's like a normal triple-A flight," LeBlanc said. "I'll take it any day of the week to get here."
Scioscia said he did not know if Josh Hamilton, who has missed the past two games of his minor-league rehabilitation assignment because of soreness in his surgically repaired left thumb, would play for Salt Lake on Sunday night.
The Angels open a four-game series in Seattle on Monday, followed by a three-game series in Oakland. Scioscia said he hoped Hamilton could join the Angels in Seattle "or, at the very latest, Oakland."