Hart is the coach of his 12-year-old son's little league team and was at Chase Field with the young ballplayers for Friday night's game against the Arizona Diamondbacks.
Hart took time to chat with former teammate Ryan Braun, who signed autographs for the little leaguers.
Hart made his major league debut with the Brewers in 2004 and played for Milwaukee until 2012. The two-time All-Star ranks eighth in Brewers history in doubles (211), is tied for sixth in triples (33) and is 11th in home runs (154). Hart, who battled injuries in the latter part of his time in the majors, left the Brewers after signing a one-year free-agent contract with the Seattle Mariners prior to the 2014 season. He last played for the Pittsburgh Pirates in 2015.