NEW YORK -- For weeks, rival teams presumed the Mets would sell off pieces as general manager Brodie Van Wagenen’s offseason plan went awry. Even after sweeping the Pirates on Sunday, the Mets remained in fourth place in the NL East, trailing seven teams in the Wild Card race.

But the Mets did not sell -- at least not yet. They instead became the Trade Deadline’s flashiest buyers, acquiring All-Star pitcher Marcus Stroman and cash for a pair of pitching prospects on Sunday.

“NEW YORK! Where I was born. Where my heart lies. Where my family resides,” Stroman, a Long Island native, wrote on Twitter. "Crazy excited for this part of my journey. Some things were meant to be!”

• Stroman: Trade to Mets 'meant to be'

To acquire Stroman, the Mets sent pitchers Anthony Kay and Simeon Woods-Richardson, their fourth- and sixth-ranked prospects, to Toronto, further weakening a system that lost blue-chippers Jarred Kelenic and Justin Dunn in a seven-player deal with the Mariners last offseason. The Mets could still reinfuse their farm system by trading Noah Syndergaard or Zack Wheeler this week, and have had extensive talks regarding those pitchers, according to sources.

The Trade Deadline is not until 4 p.m. ET on Wednesday.

Stroman, 28, posted a career-best 2.96 ERA and 3.52 FIP in 21 starts for the fourth-place Blue Jays. Because he is under team control through the end of next season, Stroman is more than just a rental, giving the Mets a readymade rotation member locked in for 2020. That’s no coincidence, with team officials insisting any deals made before the Deadline would be with an eye toward improving the 2019-20 teams. Stroman is still owed approximately $2.5 million on his $7.4 million contract, though the Blue Jays sent the Mets some cash in the deal to offset his salary. He will be due a raise through arbitration this winter.

With that price tag comes the promise of elite production. In six seasons with the Blue Jays, Stroman is 47-45 with a 3.76 ERA, plus a 4.40 ERA in five postseason starts.

Rather than rely on the strikeout, Stroman uses his five-pitch mix to generate ground balls; no American League pitcher has done so at a higher clip than his 56 percent mark this season. Stroman has also more than doubled his curveball usage from 2018 to '19, throwing that pitch over a third of the time. He will now induce those grounders in front of a Mets infield that is one of the most porous units in baseball: The Mets entered Sunday’s play with baseball’s 28th-ranked defense.

“My body feels great, arm feels great,” he said earlier this month. “It’s kind of a nod to the offseason program I had. My second half, I feel, is going to be really strong. I feel like I’ve always been a second-half pitcher. I’m just looking to carry each start into the next one.”

The trade offers a homecoming for Stroman, a Medford, N.Y., native who played against Mets starter Steven Matz in his youth.

"Marcus is a dynamic talent who will bring tremendous passion to our team and energy our fans will truly appreciate,” Van Wagenen said in a statement. “As a Long Island native, we believe that Marcus will thrive playing in New York."

Kay is also from Long Island, and before the deal, had an outside chance to debut for his hometown team in September. Instead, the Mets sent Kay to the Blue Jays following a dominant stretch that saw him go 7-3 with a 1.49 ERA in 12 starts at Double-A Binghamton. The left-hander struggled after a promotion to Triple-A Syracuse, posting a 1-3 record and 6.61 ERA.

Woods-Richardson was the Mets’ second-round pick in 2018. He impressed Mets officials this spring with his upper-90s fastball, which he used to strike out 97 batters in 78 1/3 innings at Class A Columbia. In sum, Woods-Richardson posted a 4.25 ERA at that level.

The deal leaves the Mets with only two of their top 12 prospects, Andres Gimenez and David Peterson, playing above Class A ball. But trades of Syndergaard or Wheeler could still bolster the system, as Van Wagenen looks to make good on his mission statement of winning “now and in the future.” Wheeler is an impending free agent, making him an obvious candidate to head elsewhere as the Mets look to improve their farm. Team officials have shown a willingness also to deal Syndergaard, who is under team control through 2021. In either event, with Stroman off the market, the Mets control two of the top few pitchers available for contenders to acquire.

Syndergaard, who has been the subject of heavy trade speculation since last winter, tweeted a picture late Sunday with the words: “I have no idea what’s going on.”

“It’s completely out of my control,” Syndergaard said last week, “so I’m not going to waste much energy thinking about those things.”