Floyd Mayweather and arm/shoulder injuries?

This was brought up briefly in another thread. So Floyd does his best to take most of the steam out of the punches that hit or graze his arms, elbows, shoulders by movement but it also looks like he gets hit pretty hard there at times and that can't feel too good when it's a world class puncher. For a guy who uses the shoulder roll so consistently for 12 rounds has he gotten injured due to this or atleast felt very sore afterwards on those areas? Would be interesting to see him talk about this in an interview as well.