He was indeed. Served in WWll with many other baseball greats. Saw a program not long ago which featured many of those who served. Yogi was a Navy gunner and participated in D Day Invasion. One humorous part of the Program was about 2 Red Sox greats. Ted Williams and Johnny Pesky. Both Pilots. Pesky related how he flew with Williams. He said Williams told him he was a real good 2nd baseman but a lousy pilot. Pesky laughed as he related that and said Williams was right, I wasn't all that good. Joe Coleman, Bob Feller, Monty Irvin, and many others were featured. Great ballplayers and even better men.A true American hero.