The Chargers conducted their final full practice of preseason on Tuesday. San Diego will conclude the preseason by taking on the 49ers in San Francisco on Thursday night.

“We had good practices during the week,” coach Norv Turner said. “Today was more about making sure our guys had a little preparation for the 49ers game. It was a lighter practice in shells [because] it is two days before the game. I thought the mental preparation was good.”

Gaither has MRI: LT Jared Gaither (back spasms) underwent an MRI on Tuesday and did not practice. Gaither hasn't participated in a full practice since the first day of training camp, which he exited early. Gaither has participated in an occasional walk-through and began working out on the rehab field last week.

“Our plan is to get [Gaither] ready to play as soon as he can be ready to play,” Turner said. “We are working hard to get that done. Right now, he is not ready to play.” Turner expected Gaither would play in Week 1, but that is now in doubt. “If he doesn’t practice it’s going to be hard for him to play in the opener,” Turner said.

Rivers and Gates likely to play: QB Philip Rivers and TE Antonio Gates sat out last Friday’s preseason game against the Vikings. Despite the O-line giving up six sacks in that game, it now appears both will at least play one series on Thursday. “I’d like them to play,” Turner said. “It would be good for them to get playing time.”

Mathews ramps up rehab: RB Ryan Mathews underwent an evaluation on his broken right clavicle on Monday. “It was good,” Mathews said. “It was right where I am supposed to be. Right now, I just need to take it day-by-day, stay positive and keep doing what I am doing.”

The positive evaluation allowed Mathews to take his rehab up a notch. He ran wind sprints up a steep hill while carrying a football in his right hand on Tuesday. “It’s just getting my cardio up,” Mathews said. “[I’m] just trying to maintain stuff that I am not able to do on the field by running the hills and running with the sled.”

Willie needs work: WR Mike Willie (undrafted, Arizona State) has had an excellent training camp and has performed well in preseason. With the release of WR Roscoe Parrish on Monday, Willie has a chance to beat out WR-KR Richard Goodman for the final receiver spot. Turner, however, believes Willie still needs to improve his overall game. “I’d just like to see him be more consistent,” Turner said. “He is a young guy that is all over the place. He has shown that he can catch, but he is not a very disciplined player right now.”

Injury updates: RB Curtis Brinkley (strain), CB Marcus Gilchrist (hamstring), Melvin Ingram (thigh), RB Mathews (clavicle), CB Quentin Jammer (hamstring), TE Dante Rosario (unknown), ILB Demorrio Williams (unknown) and CB Shareece Wright (unknown) worked out on the side and did not practice. Also did not practice: WR Vincent Brown (ankle), DT Antonio Garay (left foot) and LT Gaither (back spasms). C Nick Hardwick (concussion) and S Darrell Stuckey (concussion) observed. Rex Hadnot (knee) returned to practice after missing Monday.

What’s next: The Chargers will hold their final practice of preseason with a walk-through on Wednesday morning.

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