Olsen (4-3, 5.60 ERA) had never previously won consecutive decisions over his two-season career before he his victory on Sunday at Colorado. The left-hander allowed three runs, six hits and a walk in 6 2-3 innings of the 4-3 win.
“Confidence is definitely building,” Olsen, 22, said.
Olsen is 4-0 with a 3.38 ERA in five starts with an extra day of rest.
Padres (32-29) right-hander Clay Hensley (4-4, 4.15) is coming off a 3 2-3-inning outing, the shortest of his 10 starts this season. Hensley, a converted reliever, allowed four runs, five hits and a career-high seven walks in a 5-2 loss on Monday at Milwaukee. Hensley walked four of the first eight batters he faced and threw 48 of his 87 pitches for balls.
“It’s pretty embarrassing,” said Hensley, who has allowed one run over two career innings of relief work against Florida. “I couldn’t find the strike zone. My arm felt great. I just couldn’t find the location.”
Hensley has struggles pitching under the lights this season, as he is 1-4 with a 4.97 ERA and .269 opponent batting average at night. In six day appearances, Hensley is 3-0 with a 2.70 ERA and .205 opposing average.
Hensley had won his previous two starts before the Milwaukee loss.
Hensley looks to follow another strong start by Chris Young, who struck out a career-high 12 while allowing just one run in six innings of Friday’s series-opening 3-2 win.
One day after Trevor Hoffman blew his first save of the season by allowing an unearned run, he gave up another run in the ninth inning before recording his 14th save of the season and 450th in his career.
Hoffman has pitched on three straight days.
The Marlins (21-37) have lost three of four after a three-game winning streak to begin the month of June.
San Diego’s Adrian Gonzalez went 1-for-3 with an RBI to extend his hitting streak to nine games, a stretch in which he has batted .400 (12-for-30). Gonzalez also has at least one hit in 17 of his last 18 games.
Marlins first baseman Mike Jacobs tied his career high with four hits, including a solo homer, on Friday in his first time playing in his hometown of San Diego.
“I was able to put a pretty good swing on a changeup,” said Jacobs, who had between 50 and 70 family and friends at the game. “I think it definitely pumps you up more to be playing in front of your family.”
Florida left fielder Josh Willingham sat out on Friday and is expected to miss the entire series because of a strained left hand and lower back stiffness.