Landry and teammate Kenyan Drake were ejected in the fourth quarter of Sunday's loss to the Buffalo Bills. Landry was an instigator in the brawl that led to the ejections.
"This last game was probably the pinnacle of what I've ever seen with him during a game," Gase said. "I don't think I've ever seen it get to a level where it was extremely bad. But the last game was about as embarrassing as I've seen in a long time. It was something we can't have happen."
Landry, who led the NFL with 112 receptions, can become a free agent this offseason. He has said he wants to remain with the Dolphins, and they've said they want him back, but his volatile personality is cause for a concern - especially on a team that went 6-10 in part due to a lack of discipline.
Landry said he was defending himself in the fight but acknowledged the ejections hurt the Dolphins' comeback bid. They trailed 22-9 at the time and lost 22-16 .
"We're going on our last drive, and two of our best players on offense aren't in there," Gase said. "That was very frustrating to watch. We need way better control from our best players in the heat of the moment."
Landry's latest meltdown will be something to consider in deciding his future with Miami, Gase said.
"You can't take one isolated incident and overreact, but at the same time we've got to make sure we look at everything we've been doing over the last couple of years," the coach said. "You look at the body of work and see what direction we want to go."
Landry's body of work in four seasons with Miami includes 400 catches, an NFL record for a fourth-year player. He is by far the most high-profile Dolphins player eligible for free agency.
"Philosophically we want to draft, develop and keep as many of our own as possible," executive vice president of football operations Mike Tannenbaum said. "So we'll see what happens with Jarvis and a few other noteworthy free agents. In a perfect world we'd keep them all, but there is a salary cap."
Gase said he expects Ryan Tannehill to return as the starting quarterback in 2018 after missing the entire season because of a knee injury. He indicated he doesn't expect quarterback Jay Cutler to be back.
How would the season have been different had Tannehill stayed healthy?
"I'm pretty sure you know my answer," Gase said with a slight smile. "But it didn't happen."
Gase also said veteran leadership needs to improve next season.
"It's never going to be the way we want it until guys take control of this thing," he said. "You need your leaders to step up and be vocal."
More AP NFL: http://pro32.ap.org and https://twitter.com/AP_NFL
Follow Steven Wine on Twitter: http://twitter.com/Steve_Wine
Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.