Strop, who had a strong year before being sidelined with a leg injury late in the season, will make $6.25 million next season for the Cubs.
In 60 appearances during the 2018 campaign, Strop put together a 6-1 record and a 2.26 ERA, striking out 57 batters in 59.2 innings of work. He also compiled 13 saves, and did a strong job filling in for closer Brandon Morrow in the second half of the season.
The decision on Strop comes just one day after the Cubs opted to pick up the contract option on pitcher Jose Quintana. The team has yet to decide whether they will pick up the 2019 contract option for pitcher Cole Hamels.