TEMPE, Ariz. -- The Arizona Cardinals' offense continued to take hits Friday when wide receiver John Brown and left guard Mike Iupati were ruled out of Sunday's game at Indianapolis. Neither player practiced all week.
The offense was already reeling from the loss of running back David Johnson, who was placed on injured reserve Tuesday with a dislocated wrist. He'll miss at least eight weeks.
Brown, who aggravated a quadriceps injury that plagued him in training camp, had four catches for 32 yards in a Week 1 loss to the Detroit Lions.
"It's just a matter now of the next guy to step up and go, because I don't know when he's going to be healthy," head coach Bruce Arians said.
Recently signed offensive lineman Alex Boone will start in place of Iupati, who played last weekend despite a triceps injury.
"It's football for him," Arians said of Boone, who signed on Sept. 5. "[Center] A.Q. [Shipley] is keeping him abreast. [Boone] knows football, so it's just a matter of learning our calls."
Left tackle D.J. Humphries was also ruled out, but he was already expected to miss at least this week with a strained MCL suffered in Detroit. John Wetzel will start in Humphries' place.
Arians said he doesn't "feel great" about the left side of Arizona's offensive line, which will feature two new starters this weekend.
"But those guys have played a lot of football," Arians said. "I've seen Wetzel play better football than he did last week, so with a week's work he should play better this week."
The rest of the questionable Cardinals will be game-time decisions, including tight end Jermaine Gresham and inside linebacker Deone Bucannon, Arians said.
Bucannon will be limited if he makes his 2017 debut, Arians said. Bucannon missed all of OTAs and minicamp, and most of training camp as he recovered from offseason ankle surgery.
"I'm going to be careful with that one," Arians said.
Arians said tight end Troy Niklas, who appeared on the injury report Thursday with a hip ailment, will play against the Colts unless he suffers a setback before the game. New tight end Jim Dray, who Arizona re-signed on Friday will have a role in certain packages on Sunday, Arians said.
All of the injuries on offense will present a "great opportunity" to young players, said Arians, who added that he's eager to see whether young players like running back Eli Penny, wide receiver Chad Williams and tight end Ifeanyi Momah can step up.
Penny, who played one offensive snap in Detroit, will have an offensive role this weekend, Arians said.
"I think things are slowing down now," said Williams, who was inactive in Week 1. "I'm playing a little faster. ... We're jelling together. We're starting to know each other, what we do."