There are almost no meaningful in season metrics for relief pitchers. There just isn't enough sample. At this point, you could look to changes in ground ball rate and strike out rate from career or last three season norms. It is still too early to point to a change in walk rates for any of the Twin relievers. The pitch level data would tell more. Has there been a drop in velocity? Has there been a change in spin rate?... Compared to the last three years, Belisle's ground ball rate is the lowest it has been and his strike out rate is better than his year with the Rockies but lower than his seasons with the Cardinals and Nationals. He did face more pitchers in the NL increasing those NL strike out rates. His velocity is in line with that of the last three years. There is little else on his fangraphs page useful to support an argument that he brings a different level of skill from the previous three seasons. The front office would be wise to ignore most of the batted ball data and standard statistics at this point. The skilled eyes of a trained staff are vital in this assessment. Breslow is a different case. He hadn't been effective for the last three years. The question coming into camp was whether some changes he made in the offseason would lead to better results. He also is best used as a situational pitcher. Data in his sample against only left handed batters is very small and virtually useless in this partial season sample. Comparing the last 4 seasons to when he was more effective, there is a drop in velocity that continues this year. Is he their most effective option to get out a single left handed hitter? The eyes of the staff can best make that decision. Given that 114 of 131 batters faced have come in low leverage situations, I think we know what the eyes of the staff think. There is a lot of low leverage work in the Twins bullpen, perhaps Breslow brings value in the bullpen while not pitching that is worth giving him a good share of the low leverage load.