HOUSTON -- The Houston Texans' passing game is already struggling without rookie quarterback Deshaun Watson, and on Sunday against the Arizona Cardinals, head coach Bill O’Brien expects to be without wide receiver Will Fuller.

Fuller injured his ribs in the Texans’ Week 10 loss to the Los Angeles Rams while attempting to catch a short pass in the middle of the field from quarterback Tom Savage.

O’Brien expects the Cardinals to put their top cornerback, Patrick Peterson, on wide receiver DeAndre Hopkins, and without Fuller, Arizona won't have to worry about a deep threat. In six games this season, Fuller has 17 catches for 326 yards and seven touchdowns.

Before Watson tore his ACL, Fuller and Hopkins were tied for the league lead in touchdown catches with seven each. In the two games since Watson’s injury, Hopkins has one and Fuller doesn’t have any.

Fuller’s speed -- he ran a 4.32-second 40-yard dash at the NFL scouting combine -- allowed him to take the top off opposing defenses, particularly with Watson throwing him the ball. He also created space for Hopkins. At times during the Texans’ Week 8 loss to the Seattle Seahawks, Fuller had two or three defenders running with him deep, taking attention off Hopkins and freeing up Houston’s No. 1 wideout.

Since Fuller returned in Week 4 from a broken collarbone suffered in training camp, Hopkins has said how valuable it is to have another reliable receiver on the field.

“He can do some things that I can’t do on the field," Hopkins said, "and I can do some things that he can’t do, so I feel like we complement each other’s game very well."

In Fuller’s absence, wide receiver Bruce Ellington could see additional touches. Ellington, who signed with the Texans (3-6) after Fuller's camp injury, has 19 catches for 231 yards and two touchdowns In his past two games with Savage under center, Ellington been targeted 17 times, and O’Brien said he wants to see the receiver get the ball even more going forward, particularly with the Texans’ lack of depth behind him.

“Other guys are going to have to step up. Bruce is running good routes,” O’Brien said. “Bruce needs to get the ball more. Bruce Ellington, he’s doing some really good things out there. Hop [Hopkins] is Hop, everybody knows what he’s doing this year. Hopefully Braxton [Miller] can contribute in some way, shape or form at receiver.

“So I think there’s some different guys that have to step up in the absence of Fuller.”