Oblique injuries seem common to all teams. There is a lot of rotational force for hitting and pitching. Players strength train their legs to a much higher level than ever before and it seems that abdominal/core/oblique muscles have a hard time keeping up with the force being generated by legs. I am not a doctor, though.
Quick search of current oblique injuries from this week:
Matt Waldron (SDP) link
Sean Manaea (NYM) link
Jeff McNeil (NYM) link
Tyler Stephenson (CIN) link
Jesus Sanchez (MIA) link
Why are oblique strains so common? Link