Gurode returned to action Saturday and immediately regained his spot over the ball in front of Tony Romo.
Costa, meanwhile, might not be going far.
"Costa is going to play a lot for the Cowboys -- now. Now," Jones said, emphasizing the word the second time. "Boy, I am glad we've got him. I don't know if anyone has had a better preseason than he's had. I put him right there at the top, from my perspective, of preseason work and how impressed we've been with him."
Gurode, a five-time Pro Bowler, had arthroscopic surgery on his knee this summer. While he could have done it earlier in the lockout and healed in time for training camp, Jones continues to maintain a better-late-than-never attitude, perhaps especially now that it created an opportunity to see Costa in action.
Costa has taken control of the job from the start. Coaches praise his leadership in the huddle and at the line, recognizing what the defense is trying to do and passing along that information to the rest of the line.
He's pretty good once the ball is snapped, too.
"Since he's been here, he's been kind of a bulldog -- he scratches and claws and fights and really battles in all areas," coach Jason Garrett said. "He plays from the snap to the whistle and we like how he goes about it. It's good to know he's improved as much as he has."
Costa played the entire first half of the preseason opener against the Denver Broncos. Jones said Costa's grade for the game included "two or three double plusses."
"I wouldn't blink or lose any sleep over Costa starting a game for us," Jones said. "He certainly has played well enough to give us a lot of confidence. I have addressed that directly with the coaches and they feel the same way."
The offensive line has been in flux since the lockout ended and Jones made re-signing left tackle Doug Free his top priority.
Free indeed stuck around, and would be the only incumbent back in the same spot if Costa winds up at center.
Top pick Tyron Smith was handed the right tackle spot, replacing the released Marc Colombo, and Jones raved about the rookie's performance so far. To help ensure Smith has a smooth transition to the NFL, veteran Kyle Kosier has been moved next to him, at right guard.
Kosier started at left guard the last few years, with Leonard Davis handling the right side. But Davis was waived and Montrae Holland was given first dibs there. Holland hurt his back, triggering Kosier's move and Arkin's promotion on the left side. The Cowboys didn't want to plug Arkin in next to Smith because that would've meant side-by-side rookies.
Holland could still be an option at left guard, but the competition is more likely between Arkin and whoever doesn't end up at center, Costa or Gurode.
"We're letting things play out as they are, and see how Montrae comes on," offensive line coach Hudson Houck said. "There's a lot of moving parts at this point."
Gurode had a solid return to practice. He got a few plays off to give him extra rest and went off for his own conditioning work while teammates ran a series of sprints.
"We try to practice with a great tempo and we believe the center and the quarterback have a lot to do with everybody practicing at a great tempo," Garrett said. "So he needs to get up to speed with us, and he understands that. As practice wore on, I thought he did a good job of hanging in there and really setting the pace for us. He needs to continue to do that. He needs a lot of work, but he's an awfully good football player and it's good to have him back."
Gurode said his knee is "getting better and better every day."
"I felt like I wasn't as sharp as I should have been, but I was happy to be back out there with the guys," he said.
This was the Cowboys' first day of training camp back in the Dallas-Fort Worth area, and it began with a twist: nearly an inch of rain, the first serious amount after the temperature hit at least 100 degrees in 40 of the last 41 days.
Problem was, Dallas was supposed to work out at team headquarters because there was an all-day youth football tournament at Cowboys Stadium. But the tournament was put together by former Super Bowl MVP Larry Brown -- one of Garrett's former teammates -- and they were able to work everything out. The kids' schedule was adjusted, with the consolation prize that about 1,000 of them and their families got to watch the Cowboys practice.
"We were going to go out to Valley Ranch and use it as an opportunity to get back out in the heat and work, and I open up the curtains this morning very early and all of a sudden it was 68 and raining," Garrett said. "I said to the players, 'How big was the group prayer last night?' ... It was great to know part of the Cowboys family was a part of that thing and helped us out. It made for a good day of practice for us."
Notes: Nose tackle Jay Ratliff and cornerback Michael Jenkins also returned to practice Saturday and could play against San Diego a week from Sunday. ... Linebacker Keith Brooking and running back Tashard Choice are more likely to play the game after that. ... Cornerback Terence Newman is a bit ahead of schedule in his recovery, which means he is more likely to play the opener, Sept. 11 at the New York Jets.
Copyright 2011 by The Associated Press