The Cowboys placed Romo on the injured reserve/designated to return list Tuesday, which means he would not be able to practice for six weeks and cannot play for eight weeks. With the Oct. 18 bye, that pegs Romo's return Nov. 22 against the Miami Dolphins or possibly Nov. 26 against the Carolina Panthers on Thanksgiving.
Here's what Romo had to say in a tweet:
Thank you for all your prayers and support. No surgery needed. We're just getting started cowboys nation. See you soon— Tony Romo (@tonyromo) September 21, 2015
Coach Jason Garrett said the team is looking at all its options before determining Romo's status on the 53-man roster.
"In the next couple days we'll try to determine if that's a worthwhile option for us," Garrett said.
Later Monday, a source told ESPN's Josina Anderson that the Cowboys are planning to work out quarterbacks Christian Ponder, Josh Johnson and Matt Flynn on Tuesday.
The Cowboys benefited in not placing Dez Bryant on the injured reserve/designated to return list because they can use the tag on only one player. By not using it on Bryant, the Cowboys remain hopeful he will return earlier than eight weeks.
Romo will stay engaged in the process even though he can't play.
"Tony's such a great leader for our team and he has such a positive influence on everybody, so him being around and engaged is an important part of what his role is on the team," Garrett said. "But priority No. 1 is to be taking care of the rehab and getting himself back as quickly as he can. But we're confident he can do both those things."
Romo suffered the injury in the third quarter of Sunday's win against the Philadelphia Eagles after being sacked by linebacker Jordan Hicks. X-rays confirmed the break, and Romo had more tests Monday, including a CT scan that did not show ligament or muscle damage.
Had there been damage, Romo likely would have faced surgery. However, the time frame for his return would not have changed.
This is the second time in his career Romo has suffered a broken left collarbone. He was hurt in a Week 7 meeting against the New York Giants in 2010. He was kept on the active roster as the team held out hope for a return but was placed on injured reserve on Dec. 22 with two games to play.
At the time, the Cowboys were 5-9 and out of contention. This time the Cowboys hope to stay afloat in Romo's absence with Brandon Weeden as their starting quarterback.
Weeden completed all seven passes for 73 yards after taking over for Romo against the Eagles, including a 42-yard touchdown pass to Terrance Williams to put the game away.
Weeden started one game last year when Romo suffered two transverse process fractures against the Washington Redskins and struggled in a 28-17 loss to the Arizona Cardinals. He completed 18 of 33 passes for 183 yards with a touchdown and two interceptions.
He threw only two passes the remainder of the season.
In the offseason, Cowboys quarterbacks coach Wade Wilson called Weeden one of the most improved players on the team. This is the first time in his career he has worked in the same offense with the same coordinator in consecutive years.
With Romo sitting out of Wednesday practices for most of last year and the first two weeks of this season, Weeden has received more first-team snaps than most backup quarterbacks.
"I do think he has a poise and composure about him," Garrett said. "He's not someone who gets overly excited. I just think he plays with a good demeanor and I think the players around him have confidence in him, and he goes in and executes ball plays. He does his job. So he has to continue to do that. He's gotten a lot of reps in Tony's absence from practice the last couple of years, and I think that has benefited him. And just more than anything else, being around the system of football has helped him. The more opportunities you get to do that, the more comfortable you get."
Behind Weeden, the Cowboys are looking to call up Kellen Moore from their practice squad. Garrett acknowledged it is difficult for a quarterback off the street unfamiliar with the system to learn it quickly enough to make a difference.
"We like the options we have right now," Garrett said. "We have Kellen Moore on the practice squad, and he's a guy we brought in here for a reason. He's been around [offensive coordinator] Scott Linehan and in this offensive system, felt comfortable with him. But we're always looking to better our team. So if there's a viable option at this position or any position we certainly want to look into it."