SAN FRANCISCO -- Opportunities aren't just for rookies, as Brad Hennessey has discovered.
Hennessey, who has occupied every pitching role during parts of five seasons with the Giants, will start against the Arizona Diamondbacks in Wednesday's series finale, replacing Kevin Correia.
Correia, who is 3-8 with a 5.38 ERA, has lost three of his last four decisions and compiled a 7.84 ERA in his last two starts.
The Giants are curious to see whether they can receive an upgrade from Hennessey, who demonstrated the ability to pitch deep into games with Triple-A Fresno. He finished 7-10 with a 4.83 ERA and recorded three complete games, a rarity on any professional level, in 21 starts.
However, manager Bruce Bochy indicated that the No. 5 starter's role could be filled on a start-by-start basis and didn't rule out returning Correia to the rotation.
Hennessey began the season with the Giants but was optioned to Fresno after posting a 1-1 record with a 12.94 ERA in 11 appearances. Joining Fresno's rotation, he said, helped him establish his pitching rhythm and enabled him to refine his deliveries.
"In the 'pen sometimes, you feel like you're trying to keep your head above water," said Hennessey, who was recalled last Monday. "If you have a bad outing, the next thing you know you're at the bottom of the list, you never know when you're going to pitch and it's tough to work on things when you might [pitch] that day."
Hennessey also benefited from regaining full health. He endured digestive problems during Spring Training and said that he didn't resume feeling whole until mid-July. At about that time, he threw his first complete game.
Hennessey's desire to start full-time hasn't flagged.
"There's only one relieving role anyone would want," the right-hander said, referring to the closer's job -- which he held for much of 2007, when he led San Francisco with 19 saves.
Chris Haft is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.