Don't let the fast start fool you, this team is still rebuilding, and Kapler is testing young players.
SD had plenty of juice to start the 9th, he squeezed the ball, as did Morgan. Morgan has a good FB, but ML hitters pound 95 MPH FBs belt high over the middle of the plate, it needs to be shoulder high or on the inside edge - command is everything.
Sabremetrics misses this one, the 9th is different from a psychological basis, and some pitchers can't handle pressure (at least to start their career, some never, see Garcia's BS ratio).
Neris is the only proven closer, but he lacks faith in his splitter.
The rest are going to be a merry-go-round until some RP grabs the bull by the horns and seizes the job.
As far as the young hitters, Kapler is playing the long game, he's got a lot of talent that's probably 1-2 years away from being reliable ML hitters, so get comfortable with inconsistency.