The Oakland Raiders confirmed Tuesday that the father of coach Dennis Allen died Monday night from heart problems that caused him to be hospitalized last week.
The team said Tuesday that former NFL linebacker Grady Allen died overnight at age 66 from cardiac arrest.
Dennis Allen plans to return Wednesday night in time to coach the team against Denver on Thursday. His father played 59 games over five years in the NFL for the Falcons.
"The organization wishes to extend its most sincere condolences to Coach and his entire family," the Raiders said through the team's official Twitter account.
"When we first heard it, we were shocked," Raiders cornerback Michael Huff said. "We knew he was sick but we didn't know to what extreme. When we first heard it, like I said, it was sad. Anytime a part of our families dies, obviously, Coach Allen's a part of our family so his dad's a part of our family so anytime a part of our family dies, it's a sad moment. We know we have to go ahead and mourn but still go out there and play well. I say, get this victory for him."
Allen will miss the team's entire week of preparation for the game against the Broncos.
Oakland quarterback Carson Palmer said he understands his coach's absence.
"We understand he just needs some time away and a chance to be with his family," Palmer said. "What we need to do for him is prepare, get ready to play this game and focus on this game and be as prepared as we can in a short amount of time for when he returns."
This has been a challenging few weeks for Allen, who recently suspended linebacker Rolando McClain for two weeks for conduct detrimental to the team.
Offensive coordinator Greg Knapp and defensive coordinator Jason Tarver have assumed responsibility for preparing the Raiders on a short week.
The Raiders are 3-9 in Allen's first year with the team. He was the Broncos' defensive coordinator last season.
Information from The Associated Press was used in this report.