Dexter Fowler used to be a solid player, but he has been declining since signing his contract with the Cardinals. Even though Fowler still has another year left on his contract, right field is an area that could be substantially improved by removing Fowler as an everyday starter.
Fowler’s decline began when he signed his contract with the Cardinals. At the time he was coming off a 4.6 WAR season with the Cubs. However, in his first year with the Cardinals (2017), he posted 2.6 WAR. This still made him a solid starting outfielder, but nothing more.