He warmed up in the tunnel. He was also wearing the team issued cleats. He wasn't going to take it easy. It looked to me like a 75 mph fastball for sure. He has good location. If he were throwing that in the major leagues, he'd strike guys out. That was the same ball Jamie Moyer threw for 20 years, but when guys like Felix throw that pitch it's called a change-up.
Russ was the closer at NC State. So he also has a pitching background. He played full games in the field, and then they'd do a double switch and move him in to pitch to close out games, which is pretty common in college ball. A lot of guys that are the strong armed players in the majors were part time pitchers and full time players at a position in high school/college. Then they assign them a position in the minors.
Russ was assigned to be a 2nd baseman because he is fast, has a good arm, good range, and is a good lead-off type hitter. He just didn't make enough contact to look like a long-term answer as a major league middle infielder. He likely would have ended up as a fourth outfielder in the minors the following year, and I'm guessing that didn't appeal to him much.