ALAMEDA -- Denver Broncos coach John Fox, having been there before, realized early on his defensive coordinator had the look of one-and-done.
As coach of the Carolina Panthers, Fox hired Jack Del Rio in 2002, only to lose him after one season when the Jacksonville Jaguars hired Del Rio as their head coach.
So when the St. Louis Rams and then the Raiders came calling for Dennis Allen after a single season as the Broncos defensive coordinator, Fox expected it.
"He's a guy with what I call the 'it' factor," Fox told Bay Area reporters by conference call. "So it did not surprise me people looking for coaches in this league would be interested in talking to him."
After Allen was offered the Raiders head coaching job by general manager Reggie McKenzie, Allen leaned on Fox for advice.
"He said go there and you'll do a great job, and you're ready for the job," Allen said. "I've talked to him since then, and he doesn't give me all his secrets, but he's helped me out a lot."
Allen will line up across the field from Fox when the Raiders visit the Broncos on Sunday at Invesco Field.
Under Allen, the Denver defense went from 32nd overall to 20th and from 30th in rushing to 22nd. Fox, a defensive coach, gave Allen the responsibility to be the defensive play-caller, the same way Allen has done with Raiders defensive coordinator Jason Tarver.
"He's not afraid to make tough decisions," Allen said. "He believes in a lot of the same things I believe in. He's always had a tough, smart, disciplined team, and I believe in those things."
Allen watched last season as the offensive staff changed the Broncos' entire offensive approach on the fly to accommodate Tim Tebow, with the end result being the AFC West title.
Denver cornerback Champ Bailey said he expects the Raiders defense to be very well prepared.
"He was really big on how teams broke down and how they came out of the huddle," Bailey told reporters in Denver. "Read the story. They're telling you something when they come out and line up, so you know what to expect."
Cornerback Tracy Porter came to Denver as a free agent this season but had Allen as his defensive backfield coach in New Orleans.
"He stayed on me more than anything about finishing plays," Porter said. "He taught me to play within myself, don't try to do anything out of the realm. He believed in me and gave me more confidence week in and week out for them to put me out there."
"I told him, 'Hey, it's football.' "
Heyward-Bey joined his teammates on the field for the first time since the injury Friday but did not practice. He's listed as doubtful but hasn't passed any concussion tests, so he won't play.
Meanwhile, wide receiver Rod Streater hurt his neck during practice, leaving Denarius Moore and Derek Hagan as the lone healthy receivers other than rookie Juron Criner, who has been inactive for the past two games.
Cornerback Shawntae Spencer (foot) and tackle Khalif Barnes (groin) are out. Tight end Richard Gordon strained a hamstring Friday and is questionable, along with running back Mike Goodson (hamstring), tight end Brandon Myers (concussion) and Streater. Myers has been cleared for contact after his concussion and is expected to play.
Allen is keeping open the possibility of playing defensive end Andre Carter, who signed Wednesday, in a limited pass-rushing role.
Raiders (1-2) at Denver (1-2), 1:05 p.m. CBS