Brinson is hitting .197 with 28 strikeouts in 76 at-bats for the Marlins, who have the worst record in the majors. He batted .199 last year in his first season with Miami and missed two months because of a hip injury.
"There's no doubt in my mind that I can play up here, and that I can be one of the best players in the big leagues when I do get back," Brinson said. "I've just got to go down and find myself again. I'll be back soon."
The Marlins reinstated outfielder Garrett Cooper from the 10-day injured list. The injury-plagued Cooper started Tuesday night against Cleveland but left the game in the third inning after he was hit on the left knuckle by a 96 mph fastball from Trevor Bauer.
Cooper's X-rays were negative, and his status is day-to-day. He has been the Marlins' opening day right fielder the past two years, but because of injuries, he has played in just 18 games since the beginning of 2018.
Brinson will be an everyday center fielder for New Orleans.
"We felt it was best for him at this time to go down and sort of clear his head," Marlins president of baseball operations Michael Hill said. "We're still immensely confident in Lewis and his ability and how he will help this organization in the long term."
Brinson, now 24, was a highly regarded prospect when acquired in the trade that sent Yelich to the Milwaukee Brewers for four prospects before the 2018 season. Yelich was the NL MVP last year and ranks among the major league leaders this year in batting, home runs and RBIs.
Hill disputed the idea Brinson felt pressure from comparisons with Yelich.
"It wasn't a one-for-one deal," Hill said. "There were a lot of other pieces that make up that deal."
None of the other prospects acquired has reached the majors yet.
The Marlins put no timetable on Brinson's return from the minors.
"I wasn't getting it done," Brinson said. "It's about results up here. I've got to go down there and regroup."