Two days after the team's preseason-opening loss to the Denver Broncos, the Seahawks were back at Renton's Virginia Mason Athletic Center for the 13th practice of training camp. Head coach Pete Carroll met with the media after Monday's workout and provided several updates on Seattle's injured players. Take a look:

Tarvaris Jackson Has A Legitimate Ankle Sprain

Carroll said the ankle injury backup quarterback Tarvaris Jackson suffered in the preseason opener is a high-ankle sprain and that the team is "hoping" he'll only be out for a couple weeks.

"His ankle is legitimately sprained," Carroll said. "He got a high-ankle and we don't know how long it's going to take, guys respond differently to these. He feels pretty good about it."

The team is currently operating with two healthy quarterbacks on its 90-man roster - starter Russell Wilson and third-stringer R.J. Archer. With Jackson sidelined, Carroll said Seattle is exploring the option of adding another arm.

"We're looking at it," Carroll said. "We worked out a guy today."

Carroll said wide receiver B.J. Daniels would be the team's third quarterback in a game situation. Daniels has worked at quarterback for the Seahawks in the past but late last season made the switch to wide receiver, where he'll continue to compete while taking "some reps every day" at quarterback.

"We know right now that B.J. will go in a game if we need a third quarterback and that's with great fortune that he's here with us, been in the system and all that," Carroll said. "So we can pop him right in."

Chris Matthews Could Make It Back In 10 Days

Wide receiver Chris Matthews, hurt in the preseason opener after diving for a loose football on special teams, has a "slight shoulder sprain" to his AC joint.

"He's got a chance to make it back in about 10 days," Carroll said. "And it could be quicker."

Richard Sherman & Will Blackmon Are Day-To-Day

Cornerbacks Richard Sherman (hip) and Will Blackmon (groin) both sat out the preseason opener with what Carroll dubbed minor injuries.

"They ran today for the first time, so it's just a process of getting them back," Carroll said of Sherman and Blackmon on Monday. "I don't know when they'll return. Both of them had slight strains, so we just didn't want to aggravate them. That'll be day to day, they'll show us how they progress."

To compensate, the Seahawks signed a pair of defensive backs on Monday morning, adding rookie Jeremy Crayton, who participated in the team's rookie minicamp on a tryout basis this past May, and second-year pro Keelan Johnson, who has spent time with the Miami Dolphins, Philadelphia Eagles, and Dallas Cowboys.

"We need legs at corner right now, so we give these guys a chance, guys that we had worked out," Carroll said. "We can see that we're a little bit behind with Sherm and Will not being able to make it back right away and then [Mohammed] Seisay going down, too. So we just needed some legs right now, but they'll get a chance. They got tested today pretty good right off the bat."

Tharold Simon Has Been Activated Off PUP

Cornerback Tharold Simon opened training camp on the team's physically unable to perform list with a shoulder injury, but was activated on Monday and took part in light workouts. Carroll doesn't expect the third-year pro to play in the team's preseason game against the Kansas City Chiefs this Friday, pointing to the third preseason game against the San Diego Chargers as a more realistic return date.

"He's on his way back," Carroll said. "Tharold will work tomorrow if everything goes well from today. He'll work all of the drills and start to get some team work, too. Not likely to play this weekend, but by the next week he'll play. So he's back."

Earl Thomas Has A "Realistic" Shot At Being Ready For The Regular-Season Opener

Free safety Earl Thomas, who had offseason surgery on the shoulder he damaged in the team's NFC Championship win over the Green Bay Packers, started training camp on the PUP list but was activated on Aug. 5. He has still yet to fully participate in practice, but Carroll said having Thomas ready to go by the regular season is "still realistic."

"As a matter of fact we're on it right now and we're trying to gauge how many days it's going to take to get him back and figure out how to do this with him," Carroll said. "That's very much a topical issue for us right now, making sure we can get enough days to get him right, get him the work that he needs so that he can play. We're shooting for the opener."

Paul Richardson Is Rippin' It

Wide receiver Paul Richardson injured his ACL in the team's divisional-round playoff win over the Carolina Panthers this past January and also started the year on Seattle's PUP list, where he still remains. Carroll offered an encouraging update on the status of the team's first pick in last year's draft.

"Paul's rippin' it, he's running full speed, he's flying around," Carroll said. "He's well ahead of the schedule, way ahead of schedule and now it's a matter of trying to get him enough work and trust that he's ready to come back. But he's done a miraculous job of getting back. They're just blown away by how well he's running."

The Seahawks head coach noted Richardson wants to be ready for the regular-season opener, adding "he's making a bid for that."

"Paul's been through this before and understands what it is and that has always helped guys," Carroll said, referring to an ACL injury Richardson suffered in college at Colorado. "He's really benefiting from that."

Extra Points

• Cornerback Mohammed Seisay has a pulled groin. He left Seattle's preseason opener in the first half and did not return.
• Cornerback Douglas McNeil III played with a sore ankle this past Friday. He didn't practice Monday but Carroll said he has a chance to make it back in a few days.
• Defensive tackle Jesse Williams has a sore knee. Carroll said he should return to practice in the next couple days with the hope that he'll play again this week.
• Carroll didn't specify the injury, but noted offensive lineman Jesse Davis is "banged up." Earlier Monday, assistant head coach/offensive line coach Tom Cable said Davis would be out of action for a while.
• Linebacker Quayshawn Nealy was carted off the field toward the end of Monday's practice. Carroll said Nealy "sprained his ankle a little bit."
• Linebacker Kevin Pierre-Louis and defensive linemen Demarcus Dobbs and Julius Warmsley returned to action on Monday. Carroll expects all three to play against the Chiefs this Friday.
• Carroll said defensive end Frank Clark played through the preseason opener with a sore ankle - Clark still managed to post a game-high nine tackles and force a fumble. Carroll said Clark "tweaked" his ankle in practice last week.
• Cornerback Jeremy Lane (arm/knee) remains on the PUP list. Carroll said Lane is further behind in his recovery process than Richardson, who suffered his ACL injury a couple weeks prior to Lane in the 2014 playoffs.