The crowd gave a nice ovation as Collins strode toward the mound. He waved and, from the windup, delivered a strike to Red Sox manager John Farrell, who was stationed behind the plate.
"We respect his courage, we respect his choices," Farrell said. "This is an opportunity to showcase that at the time when this was a possibility of coming out, we had said we were an organization that embraces all. I think this is a very small way of showing that."
Collins, a current free agent in the National Basketball Association, made the decision to come out publicly in May in an article he wrote for Sports Illustrated. The 7-foot center recently finished his 12th NBA season, spending part of the year with the Boston Celtics.
Collins, who was not available for comment, embraced David Ortiz as he walked off the field.
Red Sox outfielder Mike Carp said he admires Collins' decision.
"It's not something that's been open in professional sports," he said. "Obviously he's the first person to do it, so kudos to him. That's a lot of pressure to come out and say that publicly."
Paul Casella is a reporter for MLB.com. Follow him on Twitter @paul_casella. Michael Periatt is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.