One of the unfortunate by-products of training camp and pre-season is that sometimes injuries happen. Some, like Robby Fabbri's last year, can keep a guy off of the roster. There's no risk of that in this case, but I am sure that Robert Bortuzzo would rather not've left the ice today.
From Jeremy Rutherford's Morning Skate:
He was a "partial" participant before Saturday, when he skated in back-to-back sessions. But a day later, Bortuzzo left the Blues' scrimmage on Sunday before it was over.
Blues coach Ken Hitchcock was in the stands for the scrimmage, which was led by his staff. When asked if it was planned for Bortuzzo to leave the practice early, Hitchcock replied: "I'm not sure. That was really the coaches' call on that. He went through the whole day yesterday. I don't know if they just pulled him out in the scrimmage part. It's still kind of him working with (Blues trainer Ray Barile)."
The most gotten out of the team regarding the injury is that it's lower body, and it's assumed that Bort is now day-to-day.