BALTIMORE — Gerrit Cole still needs at least one or two more rehab starts before he might be ready to rejoin the Yankees. But before Ryan Weathers made a case for keeping his rotation spot once Cole returns, potentially by the end of this month, Aaron Boone watched his ace’s latest rehab start Monday morning and came away impressed. Cole built up to 77 pitches across five innings with Double-A Somerset on Sunday night while striking out eight. “Really good,” Boone said before a 3-2 loss to the Orioles at Camden Yards. “Ripped his last heater 99 [mph] for another punch. I thought [Sunday] — working on things every time prior, and not that he wasn’t [Sunday], but I think it was a little more of a competitive Gerrit trying to get outs. I thought he threw the ball really well. Stuff was really good. Another good step for him.” Gerrit Cole is pictured after the Yankees’ May 2 game.…