SEATTLE -- The last wave of September callups arrived for the Mariners on Tuesday, and it includes some of the club’s top prospects, including outfielder Kyle Lewis and right-hander Justin Dunn, who’ll get a chance to get their feet wet at the Major League level in the final three weeks of the season.

Also called up from Double-A Arkansas were shortstop Donnie Walton and right-handed reliever Art Warren. The Travelers’ season ended Sunday, when they lost the fifth and deciding game of the Texas League North playoffs to Tulsa.

Dunn is the Mariners’ No. 5-ranked prospect, per MLB Pipeline, while Lewis is No. 10, Warren is No. 26 and Walton is No. 28.

The Mariners designated infielder/outfielder Ryan Court for assignment to open a needed spot on the 40-man roster for the four promotions. The 40-man had been at 37, but it's now full.

The four players promoted Tuesday all would have needed to be added to the 40-man roster this offseason to protect them in the Rule 5 Draft in December, which is why they were selected now. Other top prospects, such as first baseman Evan White, aren’t eligible for the Rule 5 Draft yet and thus weren’t promoted.

The Mariners now have nine of their Top 30 prospects on the Major League roster, with Jake Fraley (No. 8), Justus Sheffield (No. 9), Braden Bishop (No. 14), Shed Long (No. 15) and Taylor Guilbeau (No. 22) already on board.

Lewis, the club’s first-round Draft pick in 2016, figures to get playing time in the corner outfield spots in the final weeks as the Mariners are still without the injured Mitch Haniger and Domingo Santana, while Fraley just hurt his thumb on Saturday.

“You think about coming up as a child and dreaming about it and working toward it every day,” said Lewis, who homered in his debut during Tuesday's 4-3 win over the Reds. “It means a lot. I’m definitely just going to give it my best shot and see what happens.”

Dunn, one of five players acquired from the Mets in the Robinson Cano/Edwin Diaz deal, was the Mets’ first-round Draft pick in 2016, eight spots behind Lewis at 19th overall. He's also ranked No. 73 overall on MLB Pipeline's Top Prospects list.

Manager Scott Servais said Dunn will be used every fifth day in combination with Tommy Milone, either as an opener before Milone’s starts or coming in in relief of the veteran lefty. That means he’ll make his MLB debut on Thursday against the Reds when Milone is next scheduled to pitch.

“I really still haven’t figured out how to put it into words, other than that it’s just my childhood dream has come true,” Dunn said. “I’m excited to get out there and finally take the mound.”

Walton, Seattle’s fifth-round selection in the 2016 Draft, opened the Mariners’ eyes with a strong season at Arkansas this year, putting together a .300/.390/.427 line with 11 homers and 50 RBIs. He made an appearance as a defensive replacement for Shed Long in the ninth inning against Cincinnati.

Walton’s dad, Rob, is the pitching coach at Oklahoma State and played Minor League baseball for the Orioles. Walton said he’s been focused on reaching the Majors since his childhood, but was blown away when he was told after Arkansas’ loss on Sunday that he was headed to Seattle.

“This was always the goal,” Walton said. “Unfortunately, my dad got hurt and wasn’t able to make it. They told him he was going to get called up as a September callup, but he hurt his arm and that was the end for him. When he told me that when I was younger, it gave me more adrenaline and push to make the goal. So when it happened, I told him, ‘We did it. We did it together.’”

Warren was drafted by Seattle in the 23rd round in 2015 and moved rapidly up the system before injuries sidetracked his 2018 season. But he bounced back this year with a 1.71 ERA and 15 saves in 29 outings for Arkansas.

The 26-year-old got tears in his eyes when talking about how he learned he’d been promoted to the Majors on Sunday.

“It’s hard to explain,” Warren said. “It’s surprising. It’s exciting. It’s thrilling, the thrill of my family coming out here at the last minute, the thrill of finding out with Dunn and K-Lew and Donnie. I’ve been playing with K-Lew and Donnie for the last few years. It’s hard for me to describe it in just a few words. It’s truly unbelievable.”

The newcomers helped Seattle set an MLB record for most players used in a season. The club has employed 65 players, topping the record of 64 set by Texas in 2014.

Worth noting

• Shortstop J.P. Crawford is near full recovery from the strained right hamstring that has sidelined him the past 10 days and could return as soon as this weekend, Servais said.

• Fraley had an MRI on his sprained right thumb, but Servais was still awaiting word on the seriousness of the injury. The rookie outfielder hasn’t played since colliding gloves with teammate Mallex Smith in Saturday’s game in Houston.