Kyler Murray's 21-day practice window opened Wednesday with the Arizona Cardinals designating him to return from the physically unable to perform list.

The Cardinals' quarterback has not practiced with the team since he tore his ACL last December and has been on the PUP list all season. Murray is eligible to return at any time but will likely not get into a game for a few weeks. Should the full three-week window be needed, he would make his return for Arizona's Nov. 12 game against the Atlanta Falcons.

Getting a quarterback up to speed in a short period of time isn't anything new for Cardinals offensive coordinator Drew Petzing. While quarterbacks coach with the Cleveland Browns last season, Petzing had to get Deshaun Watson prepared to play following Watson's six-game suspension.

"It's a unique ask," Petzing said this week. "It was something we knew at some point we were going to deal with. We have a plan in place … to make sure he's getting as much work as humanly possible within the rules."

Joshua Dobbs will remain the starter for now as the Cardinals prepare for their Week 7 trip to Seattle. It will be a bit of a balancing act for Petzing to prepare Dobbs to possibly start each of the next three games while getting Murray ready to eventually take over.

"The guy who is playing the game has got to get ready to go," Petzing said. "That's priority No. 1. But there is extra time during the day, there is downtime during practice, there are extra ways within the rules where we are allowed to make sure [Murray's] getting his reps physically and mentally. A lot of that is done with the backup [Clayton Tune] right now."

The Cardinals are 1-5 and could be in a deeper hole in the NFC West by the time Murray is ready to return. They are currently 25th in passing yards, 22nd in passing completion percentage (62.8%) and are averaging 19.5 points per game.

Arizona's next three games are at the Seahawks, home against the Baltimore Ravens and at the Browns.