Browns CEO Joe Banner said rookie outside linebacker Barkevious Mingo will undergo further medical testing this week to determine whether he’ll be able to play Sunday in the regular-season opener against the visiting Miami Dolphins.

Mingo the sixth overall pick in this year’s draft practiced Monday for the first time since doctors diagnosed him with a bruised lung Aug. 15 during a preseason game against the Detroit Lions. He participated in team drills but was limited in practice. The Browns did not practice Tuesday.

“I think that we’re pleased in how he’s doing and the fact that he’s back out on the field limited but back out on the field” Banner told the Beacon Journal Tuesday during a wide-ranging interview about the state of the organization heading into a new season. “We’ll probably know in the next two to three days whether he’ll be able to play this week. We’re still hopeful but we won’t know for sure until later in the week.”

Although Banner said Mingo will be subjected to more tests this week he declined to specify exactly when they would be conducted.

Medical personnel examined Mingo on the sideline against the Lions because he said he was spitting up blood and experiencing shortness of breath. He was transported to the Cleveland Clinic’s main campus before the game ended and spent two nights in the hospital.

Mingo insisted he did not suffer any broken ribs and said he believes his lung was bruised during the opening kickoff against the Lions but neither he nor the Browns have been able to identify a specific hit as the culprit. Despite the mystery surrounding the cause of the injury Browns coach Rob Chudzinski said last week that the diagnosis for Mingo was still a bruised lung.

Banner was asked if he’s comfortable that the diagnosis of a bruised lung stands up and whether the possibility of a congenital disorder has been ruled out.

“Well here’s what I’m comfortable with: We have absolutely the best of the best at Cleveland Clinic from emergency medicine to general medicine to pulmonary experts have evaluated this and they’ve done every test that they’ve deemed appropriate” Banner said. “And they’re very very confident in where we’re at and I have complete trust and faith in them.

“I’m not even remotely a doctor. I’ve never seen the injury before and I’ve been in the league 19 years myself. But my confidence in them and the thoroughness of them evaluating every question that’s come up of all the possibilities — that’s what they did — leaves me confident in their assessment and that they’ll make the right evaluation as to what it was and what it wasn’t and when the right time is to put him back out on the field.”

On Monday Mingo backpedaled sprinted around cones and caught passes during a linebackers drill. He warmed up with the team at the start of practice and then watched a punting drill from the sideline. He did not engage in contact during the 30-minute portion of practice open to the media.

Mingo a backup right outside linebacker who’s expected to play a prominent role in pass-rushing situations did not travel to either of the team’s final two preseason games. Last week he began running and working out in the weight room and Chudzinski said he responded well to those activities.

Mingo declined to answer questions Monday in the locker room. A Browns spokesman said Mingo won’t be made available to reporters until Friday citing his uncertain status for Week 1 as the primary reason.