A ceremony will be held at 6:30 p.m., before the scheduled 7:10 p.m. first pitch.
Varitek played 15 seasons for the Red Sox and was named the team's 18th team captain in 2004, just after the team won its first World Series in 86 years.
Varitek was a three-time All-Star with the Red Sox. He was selected to the 2003, 2005 and 2008 Midsummer Classics and is a two-time world champion with the club.