ESPN's Todd Archer says the MRI on Dez Bryant's foot was delayed from Monday until Wednesday because Bryant didn't show up on Monday for treatment and showed up late on Tuesday. Bryant could be subject to penalties from the Cowboys. (1:16)

FRISCO, Texas -- The MRI on Dez Bryant's injured right knee was delayed because the Dallas Cowboys wide receiver was absent from Monday's treatment for injured players and Tuesday's meetings, sources confirmed.

Bryant was hurt in Sunday's victory over the Chicago Bears. Injured players are required to report for treatment the following Monday, even though it is the players' day off. The Cowboys had a conditioning workout and meetings on Tuesday, but Bryant was unable to get to an MRI since the team does not yet have an imaging device at its new facility.

The MRI took place Wednesday morning. Bryant was diagnosed with a hairline fracture of his tibial plateau in his right leg near the knee, according to a source.

Coach Jason Garrett refused to explain the reason for the delay when asked multiple times earlier Wednesday. Left guard La'el Collins, who suffered a sprained right big toe in Sunday's game, had his MRI performed Monday, and the Cowboys knew of a treatment plan the same day.

Players are subject to fines for missing meetings and treatment sessions. The Dallas Morning News first reported Bryant's absences.

"I don't want to get into the whole medical procedure," Garrett said. "We have this information now with Dez, and we're going to take his situation day by day. We'll evaluate his status for the game as the week goes on."

Garrett would not rule Bryant out of Sunday's game against the San Francisco 49ers, but a source told ESPN NFL Insider Adam Schefter that the injury could sideline Bryant for up to three weeks. Bryant did not practice Wednesday, but Garrett said the wide receiver worked out.

"We're hopeful that he'll be able to play," Garrett said.

Bryant missed only six plays after he was injured during the second play Sunday when Bears linebacker Christian Jones dragged him down after an 11-yard gain. Bryant's knee and ankle got caught under Jones, and Bryant went to the ground before getting off the field.

He finished the game with 3 catches for 40 yards, including a 17-yard touchdown in the fourth quarter. Bryant played 52 of 68 snaps, but he wasn't on the field late in the fourth quarter as the Cowboys attempted to run out the clock.

If Bryant can't play Sunday, Brice Butler, who has 1 catch for 16 yards in 3 games, would move into the starting lineup.

Rookie quarterback Dak Prescott said Bryant's potential absence does not affect the Cowboys' plans.

"I don't really pay attention to who I'm throwing to," said Prescott, who has connected with Bryant 11 times for 150 yards and 1 touchdown this season. "I just go through my reads. Whoever's open gets the ball. So, I mean, hope [he] gets well, is well really, really soon, but it doesn't really affect this offense."

ESPN staff writer Nick Wagoner contributed to this report.