BEREA, Ohio -- Given Corey Coleman's history with hamstring and other soft tissue injuries, the sight of him standing on the sidelines at Browns training camp with a tweaked hamstring is cause for concern.

The undisputed star of week one, Coleman has missed the last three practices after tweaking the hamstring last Friday while lighting it up in the intrasquad scrimmage, and might have to sit out the preseason opener Friday night in Green Bay because of it.

The No. 15 overall pick's injuries at Baylor are well-documented, and the Browns know they have to proceed with caution -- or risk losing him for the early part of the season.

"For me, a hangnail would be concerning if you have that kind of speed (4.37),'' receivers coach Al Saunders said Tuesday. "Our trainers are phenomenal. He was kept out of practice (the past three days). He's had a history of soft tissue injuries. He's had three or four hamstring pulls. He had groin surgery recently. We just want to make sure he's right and ready to go.''

Coleman redshirted his freshman year at Baylor because of hamstring injuries, and was still plagued by it in his true freshman year in 2013, when he was limited to 35 catches for 527 yards in 10 starts. The following year, in 2014, Coleman sat out the first three games of the season with a pulled hamstring and started only six contests. Still, he managed 64 receptions for 1,119 yards and 11 touchdowns.

Last season, Coleman played through a groin injury the final four games of the season, combining for only 185 yards and no touchdowns in those outings. In the previous eight games, he averaged 147 yards and 20 TDs en route to numerous Baylor records. He sat out the Russell Athletic Bowl against North Carolina and underwent sports hernia surgery in December. That's why the Browns know they have to go somewhat easy on the 2015 Biletnikoff winner.

"He's worked extremely hard,'' said Saunders. "If you asked him and his coach that was here from Baylor (Art Briles, who visited camp last week), he's never worked as hard in his life. He's never had to run as far or as hard. He's never had to be involved in the running game or be a blocker, so he's learning a lot of different phases of the game. The most important thing for us is to make sure he doesn't break down physically so he'd be unable to do the things we want him to do when he's healthy, so this is more of a precaution than anything."

As of Tuesday evening, Hue Jackson was still holding out hope that Coleman can play, but given his history, it seems unlikely. What's more, the starters will play only a series or two. The Browns have only one more practice on Wednesday before the game.

"There's a chance he can play,'' said Jackson. "I think he'll be fine, but again, I'm going to be very cautious with our players. Not just with him but with any of them that have whether it's these soft tissue injuries, hamstrings, whatever all those things are. We'll make sure that we always do the right thing and make sure that we get our guys ready to play."

Corey Coleman catches 3 big passes from RG3 in scrimmage



The Browns were plagued by soft tissue injuries last summer, and have worked hard to avoid them this year. The seasons of several players were derailed by pulled hamstrings, including Terrelle Pryor and Dwayne Bowe. Joe Haden, Duke Johnson and many other players had nagging muscle pulls last camp.

This summer, they've been kept to a minimum, but receiver Andrew Hawkins has been out for a week with a hamstring issue and now Coleman. Josh Gordon is still recovering from a pulled quad muscle from the offseason.

"They're totally unavoidable,'' Jackson. "We've done a good job because I don't think guys are staying out a long time. I don't see Corey's being something that's going to keep him out for a long period of time. Obviously, Hawk has had a history of hamstrings a little bit. We need to do that better, figure out a way to where that doesn't get him.

"The amount of running that these men do, and what I ask them to do is quite a bit. The guys have done a good job thus far, but we do have to guard against the soft tissue injuries."

Coleman admitted he'd have to "play it by ear'' in Green Bay after tweaking the hamstring during his blockbuster outing in the intrasqaud scrimmage Friday night. He caught passes of 35, 53 and 41 yards from Robert Griffin III, the latter coming in the back right corner of the end zone over Justin Gilbert for a TD.

"I felt a little bit just after,'' he said. "Fatigue nothing serious."

Coleman, who's also been returning punts, sat out the Orange and Brown scrimmage at Ohio Stadium on Saturday and the last two practices in Berea.

"It's always frustrating to sit out and watch your team go to work,'' he said. "But they're doing everything in my best interests, so I'm going to be fine. I'm good.''

The setback comes after Coleman was the undisputed star of the first week of camp. He's caught everything thrown his way, and has consistently made big plays.

"Corey's doing great,'' said Griffin. "He's got dynamic ability and the way he tracks the ball is incredible. He's a strong kid, confident kid and we've just got to keep working with him. He is a rookie but he's not playing like one and we want that to continue when the lights come on and the live bullets start to fly. So we'll stay on Corey and Corey's going to stay on himself. He'll be a pro about it.''

Teammates such as Hawkins have been comparing Coleman to his idol, five-time Pro Bowler Steve Smith, and Coleman received a shoutout on Twitter from Smith this week.

"I did see that,'' he said. "It's a blessing to even be able to chat with him and talk to him a little bit. It's unbelievable to even be put in that category with Steve Smith, as much as he's done for this game. He's a really good dude. Like I said, one of the guys I looked up to.''

Coleman's hard work in practice was inspired, in part, by Jackson calling him out publicly for not being in shape on the first day of rookie minicamp. Coleman admitted he "was gassed'' and worked overtime to be ready for training camp. Among other things, he trained with Griffin in Los Angeles.

"He just told me pretty much the sky's the limit for me,'' Coleman said after Jackson's strong message. "He's looking for big things in me. Just I've got to get in better shape. I feel the same way. I feel like I've got to get in better shape. It's going to come by me being out there practicing hard.''

What's more, Jackson has run a grueling camp, with full pads and live hitting almost every day. He's backed off when necessary, but it's still the fastest-paced hardest hitting camp since the club returned in 1999.

Saunders also stressed that the Browns will have to try to keep Coleman healthy from schematic standpoint given his size (5-11, 185).

"When you have guys that aren't big and physical, what you have to do is put a priority on the ability to separate and get speed and that's what we would do with Corey Coleman,'' he said. "Corey Coleman is a vertical player. He'll learn all those other things, but he's a vertical player. He's got undeniable speed and what we've got to be able to do is teach him to get out of his breaks with efficiency.

"We've got to be able to separate laterally as well as we separate vertically, so size, in my estimation, at the receiver position, is not an issue, but what you've got do is devise a system so they aren't in contested environments all the time."

And also keep his creaky hamstrings from tightening up.