Gronk bids farewell to good friend Ortiz

Rob Gronkowski and David Ortiz go way back.

The two superstar Boston athletes are two of the most well-known players on their given rosters. But after Ortiz played his final game with the Boston Red Sox, Gronk took to Instagram to pen his buddy a letter congratulating him on a stellar career.

"Congratulations to Big Papi on an outstanding career that he has had!" Gronkowski wrote. "It was an honor and pleasure to work with one of the best hitters of all time shooting silly @dunkindonuts music video commercials that will always live on!

"You have done it so many years with so much consistency playing at a high level every time you took the plate shows how much work and dedication you put into the game that you love," he added. "Nothing but respect. Congrats!! Enjoy retirement my friend, you deserve it big time."

Ortiz spent 14 seasons with the Red Sox, while Gronkowski is in the midst of his seventh year with the New England Patriots.