David Peterson penned a heartfelt goodbye to the Mets.

The All-Star southpaw took to Instagram to thank the organization, his teammates and fans after his time in Queens came to an end.

“From draft day to my last pitch as a Met, I am grateful to have worn the Mets uniform,” Peterson wrote, adding that the organization gave him the chance to live out his “lifelong dream.”

Peterson also thanked the front office, coaches, teammates, trainers, clubhouse staff and support staff, writing that the relationships he built with the Mets “will last a lifetime.”

“It was an honor and a privilege to be a New York Met!” he wrote.

Peterson was traded to the Cubs last week in exchange for minor-league infielder Cole Mathis, who was the No. 13 prospect in the franchise’s farm system. 

He made his Chicago debut on Saturday, allowing two runs on five hits in 5 2/3 innings after giving up a leadoff home run to the Brewers’ Jackson Chourio on his first pitch in a Cubs uniform. 

After the trade, Peterson said he was happy for the “new opportunity” in the Windy City.

“Some shock in the moment…I feel good, healthy. I went through some things early in the year I needed to clean up,” Peterson said, per ESPN. “[Feel] better now. Feel like myself back in ’24 and ’25.”

Peterson lost his role in the Mets’ starting rotation earlier this season after posting a 6.09 ERA through 68 innings. 

He was the longest-tenured Met before the deal, spending his entire big league career with the franchise since debuting in 2020. 

The Cubs were in desperate need of starting pitching, having lost Edward Cabrera and Ben Brown, who joined three other starters on the injured list, in recent days.