Phoenix, AZ (My Sportsbook) - Arizona Cardinals wide receiver David Boston is scheduled to undergo an MRI on Wednesday on his ailing knee. The Cardinals are already hurting at the position, as MarTay Jenkins was placed on injured reserve on Wednesday.

Jenkins, who suffered a fractured scapula last week against St. Louis, joins receiver Bryan Gilmore on IR. Gilmore suffered a fractured leg two weeks ago against San Francisco.

Receiver Nathan Poole was promoted from the practice squad and Ezekiel Parker, a rookie free agent cut in training camp, was signed to the practice squad.

Frank Sanders is currently the only healthy experienced receiver. If Boston can't play Sunday against Seattle, he'll be replaced by rookie Jason McAddley, a fifth-round draft pick. Arnold Jackson becomes the fourth receiver, and rookie Jake Soliday, an undrafted free agent, will be the fifth receiver.

Soliday was promoted from the practice squad last week.

Boston enjoyed a breakout season last year with the Cardinals and recorded career-highs with 98 receptions for 1,598 yards and eight touchdowns. He has 32 receptions for 512 yards this season with one touchdown.

Jenkins had 21 catches for 250 yards and one touchdown this season. He was also the Cardinals' kickoff return man.