The Padres are encouraging fans to prepare accordingly and plan to arrive early for the event.
"After speaking with a number of fans and hearing their feedback, we made the decision to move Trevor's retirement ceremony from postgame to pregame," said Padres president and chief operating officer Tom Garfinkel in a statement.
"We believe this change will make it easier for fans to plan their day around this historic event."
Hoffman spent 16 of his 19 Major League seasons with the Padres, and recorded 552 of his Major League-record 601 career saves in that time.
Many of those close to Hoffman and his former teammates will be in attendance to pay tribute to Major League Baseball's all-time saves leader.
The Padres will also retire Hoffman's No. 51 as part of the ceremony.