Benjamin Watson has called it a career. 

On Monday, Watson, a 16-year NFL veteran, Watson, announced his retirement with a lengthy post to his Twitter account. The tight end, who turned 39 in December, was slated to become a free agent when the new league year opened on Wednesday. 

"My parents tell me that as a young child I would declare that when I grew up I wanted to be 'a football player and a missionary,'" Watson wrote in his retirement post. "For the past 16 seasons God has granted me the opportunity to do both. As I walk beyond the field my sincere hope is that I was a trusted brother and friend to the hundreds of teammates and families I was blessed to share my football life with and that I earned their respect as a player and most importantly as a man." 

The 32nd overall pick in the 2004 draft, Watson won a Super Bowl during his rookie season with the Patriots. He would spend the next five seasons in New England, catching six touchdown passes during the team's undefeated regular season in 2007. After the 2009 season, Watson signed with the Browns, spending three seasons in Cleveland before signing with the Saints in 2013. In 2015, Watson set career highs with 74 receptions for 825 yards and six touchdowns. 

After missing the entire 2016 season after tearing his Achilles during the preseason, Watson caught 61 passes for 522 and four touchdowns during his only active season with the Ravens. He returned to the Saints in 2018, catching 35 passes while helping New Orleans reach the NFC Championship Game. Watson briefly retired before he re-signed with the Patriots last spring, catching 17 passes for 173 yards (his lowest outputs since his rookie season) in 10 regular season games. He caught three passes for 38 yards in his final game: New England's 21-13 loss to the Titans in the AFC wild card round. 

Watson retires with 547 catches for 6,058 yards and 44 touchdowns in 205 regular season games. In 13 playoff games, Watson caught 25 passes for 272 yards and three touchdowns. He's 24th in Patriots' history in career receptions, 28th in receiving yards, and 18th in touchdown receptions.