DENVER -- Just a week ago the Denver Broncos looked at their depth chart and were considering the idea they could keep six wide receivers when they cut the roster to 53 players.

Now they have some question marks. Wes Welker suffered a concussion in Saturday night’s preseason game, and the timeline for his availability for the Sept. 7 regular-season opener and beyond is now in the hands of the Broncos’ medical staff.

This past week the Broncos also lost Jordan Norwood for the season after Norwood, who was on track to make the roster as a depth player at wide receiver as well as a punt returner, tore his left ACL in Tuesday’s practice with the Houston Texans. Welker, because of his concussion history, will bear watching in the coming days and weeks.

He left the game with 9 seconds remaining in the first half after taking a blow to the helmet from Texans safety D.J. Swearinger. Welker got up and walked, next to a member of the Broncos' training staff, off the field and straight into the locker room.

Asked following the game about Welker’s potential recovery time, Broncos head coach John Fox said: “We’ll leave that to the medical people and he won’t come back until he’s ready to come back."

The injury occurred on a first-and-10 from the Broncos’ 47-yard line. Peyton Manning hit Welker again in the middle of the field and Swearinger hit Welker in the head as Welker lunged forward. Replays appeared to show Welker’s head dropping as he began to slide, and Swearinger hit him with a combination of forearm and shoulder. Welker got up on his own, but immediately waved to the Broncos trainers to come on to the field.

Swearinger was assessed a personal foul on the play for a blow to the head. Manning was bothered enough by the hit that, following a touchdown throw to Emmanuel Sanders on the following play, Manning ran all the way into the end zone to confront Swearinger.

“Obviously concerned about Wes," Manning said. “I just didn’t like seeing him come out of the game, a potential blow to the head, that kept out a while last year, so obviously concerned about him."

“Definitely it made me mad," Sanders said. “The fact that Peyton was addressing the situation, that means it was a bad situation. [Swearinger is] a competitor all week in practice he’s been getting into it sometimes, he lets attitude get the [best] of him."

Manning was assessed a taunting penalty after confronting Swearinger.

“Fifteen yards with five seconds left in the half doesn’t hurt you that much, I think if you’re going to get one that’s a good time to get one," Manning said.

Then asked if he could repeat what he said to Swearinger and what Swearinger said back to him, Manning said:

"I can’t. He said, 'Thanks, appreciate it, good luck to you as well.'"

Welker’s concussion in Saturday's game is the third time he has been under the league’s protocol since November. He suffered two concussions last season four games apart, and missed the last three games of the regular season.

Welker did return to play in the Broncos’ three postseason games, including Super Bowl XLVIII, wearing a helmet with extra padding. Welker has continued to wear the helmet this season as well.

According to the league's concussion protocol, even if a player is symptom-free the day following his concussion, he can return only to light exercise three days after the hit and only in non-contact portions of practice four days after the hit. The quickest a player, who is symptom-free the day after suffering the concussion, can return to a full contact practice is five days after the hit and the player has to show no symptoms compared to his base-line testing the day after the hit to even be on that timetable.

Also per the policy, once a team doctor has signed off on a player's return to the field, a doctor unaffiliated with the team and approved by both the NFL and NFL Players Association must also clear the player to return. One of the factors considered, in addition to the cognitive tests, is a player's concussion history.

Welker left the Broncos' Nov. 17 home win over the Kansas City Chiefs last season with a concussion but played the following week at New England. He suffered another concussion when he went low for a pass Dec. 8 against the Tennessee Titans.