Morales will be making just his second start in a Boston uniform. Since the Red Sox acquired him from the Rockies on May 20, 2011, Morales had been a reliever until Josh Beckett's injury forced him into the rotation. In his first start Sunday against the Cubs, the southpaw allowed just two runs and struck out a career-high nine batters.
Manager Bobby Valentine said he was pleased with how Morales, who received a no-decision in Boston's victory, responded to the opportunity.
"Those were five pretty good innings and he had more, according to him," Valentine said Sunday. "I'd like to give him a chance to do more next time."
The Braves will present Morales with a more difficult challenge than the Cubs did. They have won three games in a row, including the final two games of a three-game series against the Yankees. Rookie right-hander Randall Delgado will start for Atlanta as it looks to keep the hot streak going.
Delgado has pitched well this month, allowing only six runs in 19 1/3 innings. It has been a marked improvement on the first two months of the season, when Delgado often struggled to pitch more than five innings a game and had a 4.58 ERA in 10 starts.
Manager Fredi Gonzalez said Delgado has started to make the adjustments he needed to be successful in the Major Leagues.
"We've seen him get better and we've seen him grow," Gonzalez said. "He's been able to handle tough situations and get better the next time."
Braves: Heyward riding eight-game hitting streak
Right fielder Jason Heyward went 3-for-4 with two doubles and two runs in the Braves' 4-1 victory Friday, extending his hitting streak to eight games.
During his hitting streak, Heyward is batting .448 (13-for-29) with eight extra-base hits.
Chipper Jones, who served as the Braves' designated hitter Friday, will likely return to third base Saturday, Gonzalez said.
Jones went 1-for-5 Friday. It was the first time he has been Atlanta's DH this year.
Red Sox: Hot corner debate
Valentine said Friday he will have to make a daily decision at third base between veteran Kevin Youkilis and rookie Will Middlebrooks. Valentine conceded it will likely come down to which one is hot.
"Being I [usually] say no when you ask me that question, today I'm riding the hot hand," Valentine said. "Tomorrow might not be the case, and I always reserve the right to change my mind."
During the Red Sox's winning streak, Middlebrooks went 7-for-12 with two home runs. He stayed hot Friday, going 1-for-2 with a double.
Right fielder Cody Ross saw his six-game hitting streak end Friday night. He went 0-for-4, including a strikeout to end the game against Braves closer Craig Kimbrel.
Ross' hitting streak began before he went on the disabled list in May. He was 8-for-19 during the streak, which included three games since he returned to the Boston lineup.
Though Morales has not faced the Braves as a member of the Red Sox, he does have some history against them from his time with the Rockies. Morales made four relief appearances against Atlanta, totaling 3 1/3 innings. He allowed two runs on two hits and four walks.