McDougle was hospitalized Thursday

Philadelphia Eagles defensive end Jerome McDougle, a key part of the front four rotation in his second season, has been downgraded to doubtful on the official injury report for this weekend after a Thursday episode in which he suffered an irregular heartbeat.

The team's first-round pick in the 2003 draft, McDougle was being treated earlier this week for an upper-respiratory ailment, then complained in the late stages of the Thursday practice of shortness of breath and light-headedness.

McDougle, who has no history of heart problems, spent Thursday night in the emergency room at Pennsylvania Hospital, attended to by cardiologist Dr. Bob Norris. Medication quickly returned his heartbeat to normal, and tests continued Friday.

"He's pretty much back to normal right now, and we're just going to see what happens with him with the further tests," Eagles trainer Rick Burkholder told the local media. Burkholder described McDougle's heart as "absolutely normal" and said he could not yet explain the Thursday irregularity.

McDougle, 25, is the second NFL defensive lineman in recent weeks to suffer from an irregular heartbeat. Carolina Panthers defensive end Mike Rucker sat out all but the first series of last week's loss at Philadelphia after complaining of shortness of breath. He also had similar symptoms the previous week, in Denver, but attributed them to altitude.

Rucker practiced this week and will play Sunday against San Diego.

Eagles officials will await the results of further testing to decide whether McDougle will play this weekend. After a rookie season marred by injuries, McDougle had become a solid contributor this year, playing in every game and posting five tackles and a sack. If McDougle can't play, fellow second-year veteran and former University of Miami teammate Jamaal Green likely will take his place.

Burkholder said McDougle will continue to be closely monitored even after his release from the hospital.

Len Pasquarelli is a senior NFL writer for ESPN.com. To check out Len's chat archive, click hereInsider.