Witnesses said that Ali, mostly silenced by Parkinson's disease, didn't speak during the 40-minute presentation. He didn't have to.
"That was a big part of our recent history who walked in that morning," Giants manager Bruce Bochy recalled Saturday. "He was so charismatic. Even the young guys knew who Muhammad Ali was."
Instructor Shawon Dunston said that being in close proximity with Ali was "nice but intimidating."
"We were hoping he could be the old Ali where we could talk about everything and ask him about everything," said Dunston. "But just to see him in our presence, it was like, 'Wow, this is really him.'"
Addressing Ali's significance, Dunston observed that Ali accomplished what most people desire: "To voice their opinion and be heard."
Giants legend Willie Mays happened to make one of his customary clubhouse appearances while Ali was there. Thus, "The Greatest" (Ali) and baseball's greatest living player (Mays) who many believe is the finest ballplayer of all time were under the same roof. Actually, they briefly were in the same room, as Ali and Mays retreated to a coaches' office for a brief photo session.
"It was like Willie Mays took a back seat to Muhammad Ali," Dunston said. "We look at Willie Mays the same way. Don't get me wrong, but we see Willie every day. Willie is like a big brother to all of us, so we're used to it. Then when you see somebody who's bigger than Willie Mays, it was like, 'Whoa.'"
• Bochy said that right-hander Matt Cain, who has a strained right hamstring, has begun throwing off a bullpen mound and could be reinstated early enough to start on June 13 against Milwaukee.
Chris Haft has covered the Giants since 2005, and for MLB.com since 2007. Follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.