Gossett back to Triple-A

After turning in his best start as a major leaguer Wednesday, allowing one run in seven innings in Oakland’s 6-1 win over the Giants, Daniel Gossett was sent back to Triple-A Nashville on Thursday.

“Obviously, a tough one for us based on the way he pitched,” A’s manager Bob Melvin said of the decision, adding jokingly, “I explained to him that when you give up a run, you typically go down to the minor leagues.”

With Kendall Graveman coming off the disabled list, Melvin said Gossett was the odd man out based on scheduling; with a day off Monday, the A’s will go with four starters the next turn through. “We didn’t want to put him in the bullpen or skip him one time around,” Melvin said. “We want to keep him pitching.”

Chris Smith, who pitched well as a fill-in starter, clearly remains a candidate to rejoin the rotation next week. Gossett is likely to be back in the rotation at some point, but Melvin was not specific about when. “I would think at some point in time,” he said, “but you can’t ever guarantee that. ... He’s kind of gone back and forth with his performances, but when you pitch like he did last night, it kind of gets everyone’s attention.” A’s flotilla: Oakland’s front office arrived for Wednesday’s game on boats in McCovey Cove, joined by numerous other A’s fans sailing out of the Encinal Yacht Club.

“It was amazing,” A’s President Dave Kaval said. “We want to make this an annual thing, once a year. It’s a great way to spur interest in this team and in this rivalry.”

Kaval said that “McCovey Cove Dave,” a kayak regular during games, even traded in his Giants hat for an A’s hat. “We did an exchange in the bay,” Kaval said. “It was great. We infiltrated San Francisco and one of their most traditional fans left rooting for the A’s.”

The A’s kept their armada — A’s-mada? — a secret until the day of the event.

The next hush-hush plan on Oakland’s horizon? Expect the team to name Coliseum Gate D after Hall of Fame reliever and Fremont native Dennis Eckersley soon. Dennis Eckersley Bobblehead Day is Aug. 26.

Susan Slusser is a San Francisco Chronicle staff writer.