HOUSTON -- The Giants optioned Waldis Joaquin to Triple-A Fresno and placed right-hander Henry Sosa on the 60-day disabled list to make room on the roster for Joe Martinez to return to the club for the rubber game with the Houston Astros on Wednesday afternoon.

Joaquin made his Major League debut Tuesday. The right-hander pitched the ninth inning in the Giants' 8-1 win over the Astros, allowing one run on two hits.

"I thought it was really important to [Joaquin] to get out there [Tuesday]," manager Bruce Bochy said. "He went out there and threw strikes, and even though he gave up a few hits, you wouldn't know it the way he carried himself."

Before pitching Tuesday, the 22-year-old was 4-5 with a 2.77 ERA with one save and 37 strikeouts in 35 relief appearances, holding opponents to a .197 batting average at Double-A Connecticut. He had been recalled from Connecticut prior to Saturday's game against the Philadelphia Phillies, taking the roster spot of right-hander Ryan Sadowski.

"He was an impressive kid when he came up, loaded with confidence," Bochy said. "I think he enjoyed [getting to pitch] and he knows he can pitch up here and knows he'll get his opportunity."

In order to make room on the 40-man roster for Martinez, the Giants placed Sosa on the 60-day DL with with a torn teres major muscle in his arm.

Martinez will be making his debut as a starter at the big league level. He will be the seventh different pitcher to start a game for San Francisco this season, coming off the 60-day disabled list to make his return to the big leagues for the first time since being placed on the disabled list on April 10 after suffering a concussion and three hairline fractures on the right side of his head from taking a line drive off the head against the Milwaukee Brewers on April 9.

The 26-year-old rookie right-hander had been pitching well at Fresno, where he owned a 2.93 ERA over 37 2/3 innings. Martinez has never faced any of the Astros hitters before and is 1-0 with 6.75 ERA in 2 2/3 innings pitched out of the bullpen this season.