Perhaps by season’s end, Raiders offensive coordinator Greg Olson is going to play with a full deck. No, we’re not talking about Olson’s mental acuity, we’re talking about having access to the players he envisioned as starters before injuries mounted.

Olson still hasn’t had a game in which he has had the five offensive linemen projected as the starters. At least he’s getting close in that regard, with left tackle Jared Veldheer back at practice for the first time in more than three months and Tony Pashos slated to start at right tackle again this Sunday.

Veldheer is being realistic about things, knowing full well that it’s a long way from the training room and working off to the side with an athletic trainer to playing in an NFL game.

“It’s day-to-day,” Veldheer said of his timetable for a return to game action. “When it’s time, it’s time.”

The Raiders are two days in to a 21-day window in which they have to evaluate Veldheer. They can activate him to their 53-man roster at any time. If they opt against doing so after 21 days, their only other option is to place Veldheer on season-ending injured reserve.

Pashos said he isn’t surprised by the fact that the Raiders haven’t had a starting line for any games yet, given he has been around long enough to know that it happens.

Just the same, he said, he’s eager to see how good the Raiders can function at full strength.

“That’s the name of the game is being as healthy as you can for as long as you can,” Pashos said. “Now this tail end of the season, trying to get as many of our guys healthy will help us out in the long run. It’s good to have guys out of the training room and out on the practice field.”

Center Stefen Wisniewski said Veldheer’s impending return will have an immediate impact, based on how well Veldheer played the past three seasons.

“Jared’s a really good player, a really good pass blocker, and we’ve had some problems in pass protection this year,” Wisniewski said. “So, that’s what we need. We need some reinforcements. That will be great for us. He’ll definitely help us out a lot.”

Patching together the offensive line falls on coach Tony Sparano. Pashos said Sparano has done a remarkable job making do with so many injuries, mixing and matching and shifting around players.

Still, whatever goes on with the offense has a direct effect upon Olson’s game planning. And, just as things appear headed in the right direction in terms of the offensive line, now Olson is dealing with prepping two quarterbacks to start Sunday against the Houston Texans.

Terrelle Pryor practiced Thursday after sitting out the day before. Olson said Pryor is making progress, but it remains unclear whether his right knee will be healthy enough for Pryor to play Sunday.

To that end, Olson gave McGloin the bulk of the reps with the first-team offense Thursday because of his lack of experience — McGloin played during mop-up time against the Eagles for his only regular-season game action.

“We asked him yesterday to rest and today to show us a little bit of explosiveness and see what you can do,” Olson said of Pryor. “We never put him out there live, obviously, but we would like to see him run around and he ran around really well today.”

Without beating into the ground a well-discussed topic, Olson reiterated how he and the rest of the Raiders coaching staff were unaware of Pryor’s knee bothering him more than he let on against the Giants.

“We just have to be very careful with what he’s telling us and what we’re getting from the trainers,” Olson said, while making it clear that young players are more likely to try to downplay the severity of their injuries and play through pain.

— Olson got asked once again why fullback Marcel Reece isn’t touching the ball much in games, even though Olson, coach Allen, Pryor and others talk ad nauseum about the importance of making the most of Reece’s skillset.

Once again, Olson had a plausible reason. This time, the rationale for Reece touching the ball only three times against the Giants — all on passes — owed to Rashad Jennings’ success as the primary running back.

“I’m probably one of Marcel’s biggest fans,” Olson said. “We’re certainly always looking for ways. We had a plan last week to have him play some tailback, but we’ve felt like Rashad Jennings is running the ball very well.”

Olson said he has looked at all of Reece’s touches in recent seasons and when he excelled most. There’s a common theme, which leads Olson to believe that there’s a surefire way to get Reece more involved.

“A lot of things are to get him out in space and that’s where he was dangerous and has been dangerous and is still dangerous. To get him space, it’s obviously difficult to hand him the ball in space.

“With that being said, just more of him getting out into empty sets or one-back sets, those are things that we’ve done and Involving him more in maybe some of the heavy personnel groupings that you’ll continue to get those matchups with him.”

Reece has 28 touches in nine games, which equates to slightly more than three per game. He averaged seven touches a game last season.

— Allen said he called rookie cornerback D.J. Hayden into his office today as a means of checking into Hayden’s well being.

Hayden is out with a groin injury that he suffered in practice last week. He also is dealing with the fact he allowed three receptions for 139 yards and two touchdowns the last time he played. Now comes the realization that he likely won’t play Sunday when the Raiders travel to the place Hayden played his collegiate ball.

“I wanted to check on him,” Allen said. “I wanted to make sure that he was doing OK, get his spirits up and get ready to go. … D.J.’s going to be fine.”

Defensive coordinator Jason Tarver said Hayden is where he needs to be, from meetings to workouts.

“D.J. loves football,” Tarver said. “He’s been great. He’s been in every meeting paying attention, working on his body trying to get back. He’s a good young man, and we’re glad he’s here. I like how he pays attention. He doesn’t leave the side of the DBs that are in our room.”

Hayden was unavailable for comment during the media access period.

— Allen said Jennings’ role on special teams has been decreased in response to Jennings’ heightened role in the offense. That figures to remain the case this Sunday, if not for the rest of the season.

— Allen said the Raiders studied quarterback Case Keenum before the 2012 NFL draft, when every team passed on Keenum in the seven-round process even though Keenum had a record-setting career in college.

“We looked at him, and I thought he was a good player,” Allen said. “He set all kinds of records in NCAA, and I thought he was a good player and had a lot of the intangibles. He’s probably not the biggest, strongest, fastest, prototypical quarterback that you might look at, but he’s effective. He’s effective in college and he’s been effective in the NFL.”

The Texans signed Keenum, though they felt as if they were set at that position with Matt Schaub as the starter and T.J. Yates the backup. Keenum now is getting a chance to show what he can do, and he is making the most of his opportunity.

He has seven touchdowns and no interceptions in his 102 pass attempts, with a passer rating of 105.1.