There are worse pitchers, but I don’t think Foster is the sort of guy who pushes a team forward. He was actually okay last year, a 4.15 ERA, picked up a save. Bobby used him as a LOOGY and McBride to pitch whole innings even though this seems backwards. Lefties actually hit better against Foster, or didn’t hit; he walked a whole bunch of them. Line against righthanders was .204/.295/.278, against lefties .219/.345/.370. On the other hand, he struck out 24 lefties (in 73 AB) against just 8 righties (in 54), which suggests that the disparity is partly a fluke. Or maybe not; splits in previous years also show the pattern. With the Brewers, Yost used him as a normal reliever and not a specialist, and that might be the best use of him.
Traded to the Brewers in 2002 as part of the Braves’ first addition of a fat Milwaukee pitcher (Ray King, who really wasn’t so successful as to demand a sequel), Foster had an arm injury that derailed his career during the 2003 season. He apparently hustled himself up a shot with the Braves in spring training, pitched well enough to make the Richmond roster, and got the callup when the Braves finally had enough of Tom Martin, who made [HE WHO SHALL NOT BE NAMED] look like Goose Gossage.
Used in a very short relief role (he only once pitched more than an inning at a time, and that was just an inning and a third) he started off hot, not allowing a run in his first seventeen appearances (taking him to June 6) but after that had troubles. The appearances caught up to him, maybe. ERAs by month: 0.00, 0.00, 7.11, 7.20, 1.29, 7.36. On average, he was average, but he was never actually average.