Sean Doolittle would have been a much bigger signing if it were just a year or two ago, but at the same time, he would not have been on a list of budget signings at those times. The reason that he will be a cheap option for a closer is because of his discouraging recent stats.
Doolittle was an All-Star in 2018 when he had a 1.60 ERA in 45 innings pitched, and he had a 3.09 ERA in his 6 years prior with the Oakland Athletics. However, his fastball velocity has dropped year after year and his ERA and FIP have gone up.
His average fastball velocity was 94.7 in 2017, 93.8 in 2018, 93.5 in 2019, and then it dropped off in a big way falling all the way down to 90.7 in 2020. Following his stellar All-Star season, Doolittle had a 4.05 ERA in 2019 and then had a 5.87 ERA and an 8.28 FIP in 7.2 innings in 2020.
The Mariners could bring Doolittle in and hope that the multiple injuries that he had in 2020 contributed to his struggles. Seattle should wait on Doolittle, and if no one signs him, sign him to an incentive-laden $2 million deal. The worst-case scenario is Doolittle is the Mariners situational lefty, or he is DFA’d due to health or poor performance and it does not cost the Mariners much.