DENVER -- Mark Melancon's unusual September continued Monday with a report that the right-hander will need surgery on his throwing arm.
The Bay Area News Group reported that Melancon, who signed a four-year, $62 million deal last offseason to become the Giants' closer, will undergo surgery to alleviate chronic exertional compartment syndrome in his right forearm.
The Bay Area News Group was the first to reveal Melancon's condition, though multiple organizations had reported for weeks that the reliever was virtually certain to require some sort of procedure.
Meanwhile, Melancon remained on the active roster. According to the report, the right-hander said he wants to finish the season and delay the surgery until afterward. The Giants have not commented on the report.
"He's ready to go today," Giants manager Bruce Bochy said before Monday's series opener against the Rockies.
Indeed, Melancon struck out two and walked one in a scoreless eighth inning in the 4-3 loss.
Melancon, 32, has been on the disabled list twice this season with a right pronator strain.
Melancon amassed 98 saves in the previous two seasons, thus attracting the Giants, who led the Majors with 30 blown saves in 2016. However, he has compiled a 1-2 record with a 4.13 ERA and 11 saves while ceding the closer's role to Sam Dyson.

Moore to start again
The Giants rewarded left-hander Matt Moore for his two scoreless relief outings on Sunday in San Francisco by assigning him to start either Friday or Saturday against the White Sox.
Making only his third career relief appearance and his first since he broke into the Majors in 2011, Moore worked the final two innings and allowed one hit.
It was a welcome, if brief, contrast for Moore, who's 4-13 with a 5.42 ERA.
"He was excited about it, and it showed with the job that he did," Bochy said. "That's a great quality. You can ask a guy who's used to starting all the time. He can take it the wrong way, but he didn't. It was a good tuneup for him."
Worth noting
• The Giants are expected to summon outfielder Austin Slater and a pitcher, perhaps Reyes Moronta, from Sacramento after the Triple-A affiliate completed its season Monday.
• Right-hander Player Page for Matt Cain did not accompany the Giants to Denver to attend to personal matters.