FLOWERY BRANCH — The Atlanta Falcons can only hope nose tackle Grady Jackson and strong safety Lawyer Milloy are eligible to play at Oakland this weekend.

After giving up 192 yards rushing in last week’s loss at Philadelphia, the Falcons aren’t sure about the status of two defenders with a combined 25 years of experience.

Atlanta coach Mike Smith was pleased, however, that starting defensive end Jamaal Anderson returned to practice Thursday after missing the previous day with the aftereffects of a concussion against the Eagles.

The NFL is investigating Jackson, who has 108 starts in 161 career games, for allegedly taking a banned weight-loss diuretic. Fox Sports earlier this week reported that Jackson and a few players on other teams were listed as having tested positive for a substance that the league considers a masking agent for steroids.

Milloy, with 188 starts in 194 career games, is being investigated by the NFL after an unnecessary roughness penalty against Philadelphia tight end L.J. Smith.

Falcons coach Mike Smith declined to speculate on the status of either Jackson or Milloy after both players practiced on Thursday.

“I really can’t talk about that,” Smith said. “I don’t know anything.”

Atlanta (4-3) must contain an Oakland rushing attack that ranks fourth in the AFC and seventh overall with an average of 129.3 yards rushing. But the Falcons’ defense could be playing the Raiders (2-5) at the right time.

Oakland managed just 47 yards in losing last week at Baltimore as running back Justin Vargas, who has started the last three games, gained only 24 yards on 12 carries. Rookie Darren McFadden, the NFL’s No. 4 overall draft pick, didn’t play because of a turf toe injury.

Because they don’t know if Jackson could face a mandatory four-game suspension, the Falcons signed J’Vonne Parker, a journeyman nose tackle, to their practice squad, but they likely would use him only in a dire situation.

Parker, at 6-foot-4, 325 pounds, fills space, but he has played in only 11 career games since Cleveland signed him as an undrafted free agent in 2005.

“He’s a big defensive tackle,” Smith said. “He’s been a nose tackle in the 3-4 in his two previous stops.”
Jackson declined to comment on his status, but his agent, Angelo Wright, indicated that his client is concerned only with beating the Raiders.

“All I know is that he’s practicing and getting ready to line up this week,” Wright said. “I told Grady not to talk about it, and I’m not going to talk about it either.”

It’s unclear if Jackson might have taken product called StarCaps, which contains but does not list an ingredient banned by the NFL.

The manufacturers of StarCaps suspended sales of their over-the-counter weight-loss product on Thursday.

“We’ve received notice of the problem with the NFL,” the company said in a statement released by e-mail Thursday.

Atlanta’s run defense would be in a quandary without Jackson, Milloy and Anderson. Smith also is concerned that the Falcons lagged in their technique as last week’s game wore on and Philadelphia’s Brian Westbrook finished with 167 yards and two touchdowns.

“We have talked about it being something that we are going to have to sustain for four quarters,” Smith said. “We have talked about sustain ability. There are a lot of players in this league that have ability, but the great ones have sustain ability, having the ability to play from quarter to quarter, from game to game and from year to year. That is something that we have not been consistent for four quarters. We can put spurts together, but we know we have to get better at it.”