CLEVELAND, Ohio -- Browns defensive end Myles Garrett suffered a high right ankle sprain Wednesday when a teammate fell on it during practice, a source told cleveland.com. He'll miss at least the Steelers and Ravens games in the first two weeks -- and likely more.

Garrett, the No. 1 overall pick, will have his status updated after a couple of weeks, the Browns announced.

Garrett was inside the Browns facility in a right walking boot on Thursday. The ankle is not expected to require surgery, and it remains to be seen if Garrett will seek an independent second opinion.

He tried to gut it out in practice on the painful ankle, but succumbed shortly thereafter.

"He went as long as he could,'' coach Hue Jackson said after practice.

An MRI and further exams after practice on Wednesday confirmed the sprain.

But the Browns knew right away that it was probably serious. A source told cleveland.com on Wednesday that the club feared he could be out least four weeks.

Typically, high ankle sprains are a 4-6 week injury, but Garrett is a fast healer with a high threshold for pain.

In a related move, the Browns signed second-year defensive lineman Tyrone Holmes, who was waived by the club Sunday. To make room, they waived offensive lineman Zach Sterup. Holmes, originally a sixth-round pick of the Jaguars in 2016 out of Montana, joined the Browns via waivers as a rookie. He played in 11 games last year with one sack. He was disruptive for the Browns in preseason, with nine tackles, two sacks and one forced fumble.

This marks the second time since Garrett was drafted in April that he's been injured by a teammate in practice.

During minicamp, former Browns offensive lineman Cam Erving stepped on Garrett's left foot during a would-be sack of Brock Osweiler, and he suffered a lateral foot sprain.

Garrett was immobilized for awhile in a walking boot, and sat out of a couple of weeks over his summer break. He returned healthy for training camp at the end of July, and had no setbacks through camp and three preseason games.

It's the second high-ankle sprain Garrett has suffered in the past year, one on each ankle. Last season, he suffered a left ankle sprain early on at Texas A&M, and sat out two games. After he rushed back, it bothered him all season, and he was limited to 8.5 sacks in 2016 after recording 11.5 in 2015 and 11.0 in 2014.

"One of the worst foot injuries I have had," Garrett said at his introductory news conference with the Browns. "And I fractured a growth plate when I was in high school in a weightlifting accident. That didn't hang on for so long. It was a thing, it healed up and it went right back to working, but that ankle sprain hung on for a while."

The Aggies' medical staff recommended that Garrett rest the ankle for an extended time, but he insisted on returning after two games.

"They wanted me to get some rest, but I love my guys too much to sit out and have to watch them without me," Garrett said. "I know I wanted to be there and struggling and grinding with them. I wanted to do my best for them because they deserve it. So do the coaches, the fans and everybody else who was part of my time at Texas A&M."

He acknowledged he wasn't the same after the injury.

"I couldn't get that explosiveness, that step past the offensive tackle like I wanted, or that step to the left when I am trying to go to the guard," he said. "But I gave what I could."

Texas A&M coach Kevin Sumlin praised him for playing in pain, including during the team's bowl game.

"He could have shut it down the rest of the season, but he worked hard to get back on the field,'' Sumlin said on draft day through the Browns PR department. "Even though he wasn't 100 percent, he gave everything he had the remainder of the season including the bowl game."

It's also the second straight season that the Browns' top pick has suffered a significant injury early on in the season. Last year, receiver Corey Coleman, the No. 15 overall pick, broke his hand in practice after week two, and sat out the next six games. Coleman never caught back up after the injury, and was limited to 33 catches for 413 yards and three TDs.

The injury represents a major blow for the Browns, who consider Garrett a generational pass rusher who could transform their defense this season. What's more, they face three AFC North foes in the first four games, including the Bengals in week four.

In his absence, the Browns have Nate Orchard, Carl Nassib and now Holmes who can step in rush the passer.

Former Browns cornerback Joe Haden, who signed with the Steelers last week, said he knows how important Garrett is to the Browns' defense.

"He's looking like the first overall pick,'' Haden said on a conference call Wednesday before the injury occurred. "I was super excited when we got him. I feel like that's the pick that is a stamp. We didn't miss on that one. I could tell that from the very beginning. He just has stuff that you can't teach - his motor, his professionalism and his attitude.

"He definitely is a pro already. He is mature beyond his age. He just loves the game and loves getting after it. My bold prediction, I really feel like Myles can make the Pro Bowl his rookie year."

First, he has to get back on the field.