Brandon Brooks arrived at Lincoln Financial Field on Sunday morning before a 1 p.m. kickoff, according Doug Pederson.

"He was playing," the Eagles coach said on Monday. "He was there at the stadium ready to go when all this happened."

All this still doesn't have a specific name. The Eagles announced approximately 90 minutes before they were to face the Redskins that Brooks "began suffering an illness earlier today" and would be inactive.

Taken individually, a player missing a game on short notice during flu-cold season wouldn't be a big deal. But Brooks had been sidelined two games earlier with what was also described as a game-day illness, and the offensive lineman sat out two games - one in 2015 and another in 2014 - under similar circumstances with the Texans.

While Pederson declined to go into detail, he did acknowledge that the four game-day absences - three of which have resulted in hospital stays - could be related.

"There is a little bit of history there," Pederson said, "but it's something our medical team will do more to investigate this thing as we go."

There have been obvious short-term consequences to Brooks' short-notice scratches, and there are potential long-term ones should the Eagles discover that there is more to his illnesses. But of more importance is the 27-year old's general well being.

Pederson said that he spoke to Brooks about his recurring game-day sicknesses on Monday morning.

"He definitely wants to explore the reasons why," said Pederson, who also said that Brooks had never missed any other days because of illness. "If we can help him, I want to help him and make sure it doesn't happen again."

Asked if Brooks' illness was mental, Pederson said that he didn't know and deferred to the Eagles' medical staff. Brooks did not respond to questions via text message Monday and his agent, Joe Panos, declined to comment.

"I don't talk about the health of my clients," said Panos, a former Eagles offensive lineman.

Brooks' last-hour absences have forced the Eagles, who have been shorthanded on the offensive line almost all season, to scramble and insert Isaac Seumalo in at right guard. The rookie has answered the call, but there has been an obvious drop in production.

Pederson said that Brooks would return to practice on Wednesday and that he was still his starter, but can the Eagles rely on a player who has now missed two of 13 games because of unresolved game-day sicknesses? The coach admitted, "It can be a challenge."

The Eagles signed Brooks to a five-year, $40 million contract in the offseason. It's unclear if the Texans made an aggressive push to retain one of their homegrown players. But they did replace Brooks with free agent Jeff Allen, who signed for four years at $28 million.

Brooks missed four games from 2013-15. Last season, he was inactive in Week 7 against the Dolphins because of a toe injury and in Week 13 at the Bills because of an illness. The latter absence occurred when he started experiencing nausea and sweating, according to the Houston Chronicle, and was taken to a Buffalo-area emergency room.

"I didn't see it coming, it hit me full-force," Brooks told the Chronicle after he was released. "Annoying because it's happened before and you know what you're getting ready to go through, scary, at the same time, because although you go through it each time, you don't know how severe it's going to be each time."

Brooks said before the 2015 season that he missed the Week 6 game against the Colts the year before because of an ulcer. He was admitted to the hospital on the day of the game for what he originally termed a "stomach bug."

Two weeks ago, Brooks used that same wording to describe his sickness. Pederson said two days earlier after the Nov. 28 Packers game that Brooks "was very nauseated, throwing up . . . all day." He said the Eagles sent him to hospital for testing.

Brooks later said that he was fine and that he just needed to "stay hydrated, stick to bland foods." Asked if Sunday's illness was again "some kind of stomach thing," Pederson said that "medically" he didn't know.

"I'm not Brandon, so I can't speak for him," Pederson said. "But it's something we've got to get to the bottom of and help him as an athlete."

Pederson said that Brooks was "fine" during team meetings the evening before Sunday. The Eagles stay overnight at a Navy Yard hotel before home games. The team has several shuttles transport the players to the Linc at various times before kickoff.

Brooks had made it to the stadium, according to Pederson, but he didn't warm up. Asked when he found out that he couldn't play, the coach said he was in his office when team trainer called about 8:30, 9 a.m.

Several Eagles declined to answer questions about Brooks after the game. Offensive lineman Matt Tobin said he saw him before the game. Seumalo said that he didn't and that he was informed by phone that he would start only hours before kickoff.

The Eagles under the current ownership have had to manage many off-the-field issues for their players over the last two decades. They have practically seen it all, which makes it all the more surprising if they didn't see something potentially serious brewing with Brooks.

His four game-day absences follow virtually the same pattern, and for the time being, Brooks' health should be the primary focus.

@Jeff_McLane