Dallas Cowboys defensive end Randy Gregory practiced for the first time since the end of the 2016 season on Monday, nearly a month after he was reinstated by the league from suspension.

FILE PHOTO: Aug 29, 2015; Arlington, TX, USA; Minnesota Vikings quarterback Teddy Bridgewater (5) fumbles the ball against Dallas Cowboys defensive end Randy Gregory (94) in the first quarter at AT&T Stadium. Mandatory Credit: Tim Heitman-USA TODAY Sports

Gregory, whose third violation of the NFL’s substance-abuse policy left him suspended for all of 2017, told reporters Monday he wasn’t sure he would ever return to the Cowboys, or play football again.

“Obviously, there was a chance that I would play again if I did the right things,” he said, “but just looking at everything that was mapped out as far as what I needed to do and what I had going on in my life at the time, it was hard for me to say that I really thought I was going to be back.”

Gregory, 25, played in just two games in 2016 due to suspensions, after he appeared in 12 as a rookie in 2015. He was conditionally reinstated on July 17 and fully reinstated a week later after the league verified that Gregory had arranged for “clinical resources” in Dallas. Monday’s appearance in practice came after he spent the last few weeks working on conditioning.

“I think the last two weeks has been real fun,” he said. “I think the days, the weeks, the months leading up to this have been pretty emotional. I think I’ve learned to handle my emotions a lot better than I have in the past.”

Cowboys owner and general manager Jerry Jones told reporters Monday he expects Gregory to play in the team’s regular-season opener Sept. 9 against the Carolina Panthers.

Meanwhile, the Cowboys activated defensive tackle Maliek Collins from the physically unable to perform list, allowing him to return to practice.

Collins, 23, broke the fifth metatarsal in his left foot during the team’s offseason conditioning program in May and required surgery, putting his availability for the regular-season opener in doubt. The Dallas Morning News reported Monday that Collins, who has started 30 of 32 games through two seasons, is on target to be ready for the season.

A third-round pick in 2016, Collins had surgery on the same foot in January after playing through a foot sprain for much of the 2017 season, though he managed to start all 16 games. He also battled a similar injury to his right foot during his rookie season, when he totaled 5.0 sacks.

The Cowboys also signed former Oregon and Utah wideout Darren Carrington II and offensive lineman Jacob Alsadek, while waiving wide receiver Marchie Murdock with an injury designation and placing guard Marcus Martin on injured reserve with a torn toe ligament.

The son of former NFL safety Darren Carrington Sr., Carrington II was dismissed by Oregon in July 2017 after being arrested for driving under the influence. He quickly joined Utah, where he had 70 catches for 980 yards and six touchdowns as a senior last season. Carrington II went undrafted despite totaling 182 career catches for 2,899 yards and 21 scores in four college seasons.

Martin tore a ligament in his right big toe in the Cowboys’ preseason opener and will miss the season.

Alsadek joined the Green Bay Packers in May as an undrafted free agent out of Arizona but was waived later that month.

Murdock also went undrafted in April, signing with the Cowboys. He had 41 catches for 513 yards and five touchdowns in 2017 at Iowa State, by far his most productive college season.

--Field Level Media