Britton is likely to miss the start of the 2018 season after rupturing his Achilles tendon in December. He told ESPN at the time that he hopes to be back a "little quicker" than the six-month projections.
The 29-year-old was also slowed by injuries in 2017, including an MCL strain in his left knee. He was limited to 38 games and had a 2.89 ERA, 1.527 WHIP and 15 saves.
Britton was the most dominant reliever in baseball in 2016. He led the league with 47 saves and had a 0.54 ERA and 0.836 WHIP. He was an All-Star and finished fourth in Cy Young voting.