The Angels (14-7) won the middle game of the three-game series 4-3 on Saturday night, ending a four-game losing streak in which they were outscored 35-4.
After giving up 14 home runs in the previous four games, the Angels scored all their runs off home runs on Saturday, getting solo shots from Jefry Marte and Mike Trout and a two-run blast from Albert Pujols that broke a 2-2 tie in the sixth inning.
"We don't try to change our approach," Pujols told Fox Sports West after the win
Pujols is eight hits shy of 3,000 after he hit his fourth homer of the season and 618th of his career.
The Giants (8-12) will be looking for their first series win of the season.
Pablo Sandoval filled in for Posey at designated hitter and delivered an RBI double with two outs in the eighth inning to pull the Giants within 4-3.
San Francisco right-hander Johnny Cueto (1-0, 0.45) is set to make his first career appearance at Angel Stadium in his 11-year major league career.
Cueto has been especially strong so far this season, allowing one earned run in 20 innings. His only win occurred in a 10-1 victory against the Seattle Mariners on April 4.
Cueto pitched seven scoreless innings in each of his other two starts, a 1-0 win at the Los Angeles Dodgers on March 30, and a 1-0 loss at the Arizona Diamondbacks on Tuesday but did not receive a decision in either game. He struck out 11 in his latest outing, but was out-dueled by left-hander Patrick Corbin, who threw a one-hitter.
"If we get ballgames out of Johnny like we did (Tuesday) night, he's going to win us a lot of baseball games," San Francisco first baseman Brandon Belt said.
Cueto has made two starts against the Angels in his career. He's 1-0 with a 1.20 ERA. He beat the visiting Angels as a member of the Kansas City Royals on Aug. 15, 2015, allowing one run and eight hits in eight innings of a 9-4 win. Pujols homered off Cueto in the game and is 8-for-32 (.250) off him.
Cueto also started against Los Angeles on April 1, 2013, as a member of the Cincinnati Reds in the first interleague season opener in major league history. He allowed one run in seven innings but did not receive a decision in a 13-inning game won by Los Angeles, 3-1.
Angels left fielder Justin Upton is 6-for-20 with two home runs in his career against Cueto.
Angels starter Jaime Barria (1-0, 1.80 ERA) will also make his first appearance at Angel Stadium in the second start of his major league career.
He made his debut April 11 at the Texas Rangers and allowed one run and one hit, a home run by No. 9 hitter Ryan Rua, in five innings of a 7-2 win.
Barria was optioned to Triple-A Salt Lake City after the win, and the 21-year-old Panamanian right-hander was recalled on Friday.
"I think Jaime pitched well his last start," Angels manager Mike Scioscia told MLB.com on Friday. "He's probably throwing the ball most consistently down there of the starters."