The Raiders will be without running back Darren McFadden during their preseason open at Dallas. He has a hamstring injury.

It is not the end of the world, but McFadden needs game repetitions. He has been often injured in his two-year NFL career, which has contributed to a slow start for the No. 4 overall pick in 2008. McFadden is competing for primary ball-carrying duties with Michael Bush. So, without McFadden, Bush has the first crack to impress the coaching staff.

Again, this is not terrible for McFadden. But he does have to show he can stay healthy.

Meanwhile, the Oakland Tribune reports star Oakland cornerback Nnamdi Asomugha is getting freed to move around more than in the past. That’s a good thing. Asomugha is a difference maker. Oakland needs to get the most out of him.

Perhaps that’s one of the reason why ESPN’s John Clayton is so high on the Raiders this year.

• Apparently, Tuesday was rookie haircut day at the Raiders’ camp. No word if anyone got attacked as badly as Tim Tebow did the other day in Denver.

• The Chargers are hurting at left tackle, but Tyronne Green has proven to be a gem and he has a chance to back up Brandyn Dombrowski at left tackle when he returns. Dombrowski has the best chance of playing while Marcus McNeill holds out.

• Former Denver coach Mike Shanahan is going back to his glory days in Denver by bringing in some former Broncos’ stars to help teach the Redskins’ Shanahan’s way. Very interesting.

• The Chargers have signed strong safety Quinton Teal. He is an interesting player. He is entering his fourth NFL season. He was previously with Carolina. He played in every game last season and started the first three. He gives San Diego good depth a fairly thin spot. He can also play special teams.

The Titans are planning to make the Raiders wear their black jerseys on opening day. The Titans have the right to wear their home or road jerseys since they are the home team and they want to take advantage of the expected hot weather. At least, the Raiders know what they will be facing: major heat.