You learn more about pitchers than hitters in April. Basically what kind of stuff they have. Hitters often need time to get into a groove.
Eickhoff was consistently hitting 92-93, a very good sign, though his velocity was falling off in the 7th, which suggests adrenalin wearing off.
He stuck with the changeup, even though it's a work in progress and inconsistent, and that's a good move, hitters seem to time his cuvre the third time through the lineup.
Developing that changeup could make him a #2 starter, it provides an option that will keep teams off balance in the later innings.