Willson Contreras signed with the Cubs on July 2, 2009. And until Wednesday, they were the only organization he knew.

Contreras, regarded as one of the best offensive catchers in Cubs history, agreed Wednesday to a deal with the Cardinals, who reportedly gave him a five-year, $87.5 million contract to replace retired catcher Yadier Molina.

Contreras, 30, said succeeding Molina would be “one of the great honors of my entire life.”

“I couldn’t be more excited about coming to St. Louis,” Contreras wrote Thursday in a story for The Players’ Tribune titled “Let’s do this, St. Louis!” “It’s a dream come true, for sure. At the same time, though, I’d be lying if I tried to say this wasn’t going to be a huge change for me … like it’s no big deal.”

Contreras recalled being 16 when the Cubs signed him out of his hometown of Puerto Cabello, Venezuela, when he was “barely old enough to drive a car.”

“I didn’t know any English,” he wrote. “All I knew was baseball. And the Cubs.”

Contreras earned a World Series ring in his rookie season in 2016, the Cubs’ first championship since 1908.

“And I couldn’t be more grateful that that’s how things went for me, either,” he wrote. “I’ve been so lucky to have been a part of the Cubs family for the past 13 years. It’s been an incredible ride! I mean, winning a World Series right off the bat? In my rookie season? It doesn’t get much better. And it’s an experience I’ll never forget.”

Contreras, a three-time National League All-Star, had a .256/.349/.459 slash line and 115 OPS+ in seven seasons on the North Side. He hit 22 home runs in 2022 to become the first catcher in franchise history and 17th Cub overall to record at least four 20-homer seasons.

A first-inning grand slam May 16 against the Pittsburgh Pirates was Contreras’ 100th career home run; only two other Cubs catchers, Gabby Hartnett and Jody Davis, previously reached that milestone.

“I know I’ve given my all to the Cubs over the years,” Contreras wrote. “I did everything I could to help make the team better. I played through injuries. Left it all out there on the field. I’m proud of what I’ve contributed. So I have no regrets about turning the page. I worked extremely hard for many years to get to this place, to be in this position. It’s something I’ve dreamed about — building a career that would allow me to get to where I am right now. And I’m moving on knowing I did all I could for my team.

“But now my team is the Cardinals.”

Contreras will take on his former team for the first time in a three-game series May 8-10 at Wrigley Field.