CLEVELAND, Ohio -- Troubled second-year receiver Antonio Callaway ran out of chances with the Browns.

The Browns waived Callaway on Thursday, just hours before their big Thursday night showdown with the Steelers at FirstEnergy Stadium.

A source told cleveland.com that Callaway was suspended 10 games for violating the NFL’s substance abuse policy, and that he’s awaiting a decision on the appeal, which was heard on Friday.

The source said Callaway failed two drug tests in August after he ingested a CBD edible that was tainted with THC, the active ingredient in marijuana that’s banned by the NFL. The CBD was supposed to have been THC-free, and was sent to a lab for testing, where it was revealed it contained the substance.

The 10-game suspension comes on the heels of his four-game suspension to start the season for violating the NFL’s substance abuse policy.

He was only slightly over the NFL limit for THC in the system, 15 nanograms on the first test, and 40 on the second, the source said.

The initial four-game ban was for failed marijuana tests from last season, and Callaway hasn’t used since January, the source said.

Callaway also underwent substance abuse treatment in the offseason and was working hard to adhere to the terms of his program, the source said.

He hadn’t tested positive before the August CBD issue and hasn’t tested positive since. He’s worked hard to turn his life around and wasn’t using, the source said.

THE FULL STORY OF CALLAWAY’S SUSPENSION AND WAIVER

Their fourth-round pick last season out of Florida, Callaway was benched last week for the Bills game, and a source told cleveland.com that he was late for the game. The source said his tardiness was related to a parking issue for Callaway. Specifically, Callaway didn’t have his pass for the right parking lot and was sent to another lot, which made him about five minutes late.

Callaway was also about 10 minutes late for practice on Tuesday when it took him twice as long to get to the Browns’ facility in Berea because of a snowstorm that resulted in accidents all over the highway. A short drive took him more than 45 minutes, the source said.

Coach Freddie Kitchens said Tuesday he didn’t know if Callaway got the message from last week’s benching, but cautioned, "I’m not wavering.''

The two tardies were minor in comparison to the looming suspension, and the Browns decided they had had enough.

Rookie offensive lineman Drew Forbes, activated off injured reserve with his knee injury, took Callaway’s place on the roster.

Callaway’s departure should mean more playing time for Rashard Higgins, who caught the game-winning 7-yard touchdown pass in Sunday’s 19-16 victory over the Bills.

Browns GM John Dorsey took a chance on Callaway in the fourth round of the draft last year knowing full well he’d be a work in progress. A man of second chances, Dorsey felt Callaway had first-round talent and was worth being rehabilitated.

But Callaway was never able to live up to his promise of not letting Dorsey down.

Offensive coordinator Todd Monken revealed in August that Callaway reported to training camp out of shape. He then dropped a pass on the goal line in San Francisco with the Browns trailing 14-3 in the second quarter that was picked off by K’Waun Williams to set up a 49ers touchdown.

The drop represented a 14-point swing, and Monken called it “catastrophic.”

In the four games he played this season, he caught eight passes for 89 yards with a long gain of 41 in Denver.

Last season, he caught 43 passes for 586 yards and five touchdowns, with catches of 71, 59 and 47 yards.

The departure of Callaway marks the second key player the Browns have cut in recent weeks. They also waived defensive back Jermaine Whitehead on Nov. 4, a day after a series of offensive and threatening tweets following the loss to the Broncos.

Callaway’s departure marks the exit of the third member of the 2018 draft class in recent weeks. The Browns traded second-round offensive lineman Austin Corbett to the Rams for a fifth round pick; and fifth-round pass rusher Genard Avery to the Eagles for a fourth-rounder.