Graterol threw a bullpen session Wednesday, during which he threw only fastballs, Jorge Castillo of the Los Angeles Times reports.
Graterol has been ramping up slowly this spring following an offseason that featured inconsistent throwing. Manager Dave Roberts indicated that Graterol touched 96 mph with his fastball during his first bullpen session of the spring and that he is expected to throw another one in the coming days. Assuming that plan holds, Graterol should be ready to go by Opening Day.