But it came with no guarantees that Gray will be in the Athletics' rotation for the AL Division Series against Detroit, at least until it's officially announced.
"You can make your own assumptions," Melvin said. "I really don't want to say anything right now until we have it all decided and that probably happens at some point in time tomorrow."
Gray threw five shutout innings, Oakland had a pair of four-run innings and the Athletics closed out the regular season with a 9-0 win over Seattle in Eric Wedge's final game as Mariners manager.
The A's now turn their attention to the ALDS against Detroit that will begin Friday in Oakland, while Seattle enters the offseason with another managerial search on the docket.
Oakland is likely to start 18-game winner Bartolo Colon in Game 1 and from there they have a multitude of options.
There's Jarrod Parker (12-8), Sonny Gray (5-3), Tommy Milone (12-9), Dan Straily (10-8) and A.J. Griffin (14-10) all serving as options that Melvin can use to fill out his rotation for the remainder of the series.
"It would be nice. Hopefully I'm fortunate enough to be able to do that," Gray said. "If my name gets called I'll definitely be ready."
Oakland gave a few of its starters the finale off, while some others made cameos before getting a rest before beginning the postseason. Jed Lowrie, Coco Crisp and Yoenis Cespedes all sat Sunday, while Josh Donaldson, Brandon Moss and Chris Young were lifted early.
"We have a bigger goal right now and that is to go deep in the playoffs and probably didn't want anything freak to happen on a day like today," Donaldson said.
It didn't matter who was hitting against the Mariners. The A's scored four times in the second inning, all charged to Seattle starter Erasmo Ramirez, and four more times in the fifth.
Young got Oakland started with a two-run single in the second, followed by RBI doubles by Seth Smith and Moss. Alberto Callaspo had an RBI single in the fifth, followed by an RBI double from Josh Reddick and a two-run single by Daric Barton.
Gray (5-3) gave up a pair of singles in the first inning and walked a pair of batters in the third, but otherwise got through his final regular-season outing without any trouble. Gray struck out eight and gave up three hits. It was the 16th time in the final 19 games of the regular season that Oakland's starter allowed two earned runs of less.
Oakland finished with 96 wins, the most since reaching that total in 2003.
"He doesn't like to give up runs," Melvin said of Gray. "That's a good attribute in a pitcher. He goes out there and he's grinding on it whether it's 8-0 or 1-0. That kind of attitude really plays anywhere and to be able to continually motivate yourself for perfection and you're not always going to get it."
NOTES: Cespedes didn't play the final two games of the regular season to give his right shoulder extra rest. Oakland believes he'll be ready for the ALDS. ... Jemile Weeks got his first hit of the season with a single in the fifth inning.