Oakland Athletics relief pitcher Tyler Clippard pumps his fist after...

Oakland Athletics relief pitcher Tyler Clippard pumps his fist after the Athletics defeated the Cleveland Indians 5-4 in a baseball game, Saturday, July 11, 2015, in Cleveland. Credit: AP / Tony Dejak

About a month ago, with the Mets languishing beneath the weight of injuries, a high-ranking team official looked ahead toward the trade deadline.

"This," the official said, "is not a strategy of sitting on our hands."

Those words rang true again Monday as the Mets continued their aggressive approach to the deadline by trading for A's closer Tyler Clippard.

The Mets gave up minor-league pitcher Casey Meisner. A source confirmed that the A's kicked in $1 million in the transaction.

And the Mets might not be finished yet. A team source told Newsday on Monday that the club will continue to explore the market for another offensive upgrade.

General manager Sandy Alderson is expected to address the trade Tuesday, when his team begins a three-game series against the Padres at Citi Field.

For the second time in four days, the Mets bolstered an area of need, this time a bullpen in need of more depth.

On Friday, the Mets traded for Braves infielders Kelly Johnson and Juan Uribe. Now they've added Clippard, 30, a two-time All-Star who will take some pressure off closer Jeurys Familia, whose brilliance has sustained a relief corps that has been thinned by injuries.

Familia will remain the closer, a Mets source told Newsday, with Clippard sliding into a setup role.

Clippard, a one-time Yankee, was 1-3 with 17 saves and a 2.79 ERA in 37 appearances for the A's. The righthander has limited lefties to a .100 average (7-for- 70), another plus for a bullpen missing Jerry Blevins, the Mets' primary weapon against dangerous lefthanded hitters.

The Mets now boast a bullpen that features four players with big-league closing experience: Familia, Clippard, Jenrry Mejia and Bobby Parnell. Clippard could become an important piece if the Mets qualify for the postseason, with Mejia ineligible because of his 80-game PED suspension.

Meisner, 20, was a third-round draft pick in 2013 and is 10-4 with a 2.35 ERA in 18 starts this year. He began the season at low Class A Savannah but earned a promotion to high Class A St. Lucie.

Meisner also had been a key piece in a deal that fell through late last week, a source told Newsday. On Thursday night, the Mets pushed hard for the Brewers' Gerardo Parra, only to come away empty-handed.

Now the Mets find themselves on better footing to choose how to proceed. Thus far, they have been aggressive, moving quickly ahead of Friday's 4 p.m. deadline. But after Monday's move, they sent early signals of going in the opposite direction and waiting for prices to fall as the deadline looms.

The Mets could use another outfielder and still boast a deep base of prospects to use in a trade. They have been linked to myriad options in the market, including the Padres' Justin Upton and Will Venable and the Reds' Jay Bruce.

An executive from another club acknowledged that prices for available outfielders remain steep. "Prices are high and supply is low," the executive said. "Prices always come down at the deadline."

The Mets also could stand pat. For an offensive upgrade, they could wait for catcher Travis d'Arnaud to return from a sprained left elbow. On Monday night, he caught seven innings and went 1-for-3 in a rehab game with Double-A Binghamton.

If anything, the recent flurry of moves has asserted the Mets' standing in the market as a serious buyer. After years of skepticism from fans and media members, anything is possible. And the rest of the baseball world has taken notice.

Said one evaluator: "They aren't done."

With David Lennon