General manager special assistant Reid Nichols says Coolbaugh was kind, hard working and played the game with great passion.
The minor league coach was struck and killed by a line drive in Arkansas. He joined the coaching staff of the Tulsa Drillers just weeks ago and was standing in the first-base coach's box when he was hit by a foul ball.
He was rushed to a hospital in North Little Rock, but stopped breathing as the ambulance arrived.
Coolbaugh played 44 games in the major leagues for the St. Louis Cardinals and Milwaukee Brewers over two seasons.
Coolbaugh is survived by his wife, Mandy, who's pregnant, and two young sons, Joseph and Jacob, all of San Antonio.