He punted three times in the first half against the Eagles, and each time he planted his left foot for the kick, he felt a shooting pain.
He sat out the second half of that game, and sat out the next game as well when the leg didn't get any better. The Cowboys' medical staff ran a battery of tests on the leg, including X-rays and an MRI, but couldn't find anything.
"Last year was tough," said the 33-year-old Australian. "We didn't know what it was. They sort of missed it on the first diagnosis. They were scratching their heads. They'd say, 'Well, let's see if it improves by itself.' But it didn't. Actually, it got worse."
McBriar developed a condition known as drop foot, which prevented him from lifting his foot. But the doctors had no idea what was causing it.
Even though he had trouble just walking, he continued to play, punting in eight more games before the team finally put him on injured reserve in late December.
Right after the season ended, McBriar decided to seek another opinion.
He and his wife Erin went to the Mayo Clinic in Rochester, Minn.
"We went to Mayo just looking for a different treatment or treatments," said McBriar, who was released by the Cowboys in March and is competing against Chas Henry for the Eagles' punting job. "We were hoping maybe somebody up there would have something that could help. That's sort of what we were hoping for when we went up there."
Their trip went far better than they ever could have hoped. The doctor he saw at the Mayo Clinic, Robert Spinner, didn't offer him a treatment option. He gave him a diagnosis. And a way to fix it.
Turns out McBriar had an intraneural ganglion cyst inside the nerve behind his left knee.
"Dr. Spinner saw it on the [CT] scan," McBriar said. "He said, 'Oh, that's my specialty. I know exactly what to do.'
"I can't tell you how relieved I was at that moment. To find out that there was a cyst that was inside the nerve that needed to be removed before it got better, well, that was the best news we could have gotten. They had to go in, cut off the branch of the nerve that was taking up this fluid, and then remove the cyst itself."
McBriar had the surgery in late January. Spinner warned him that his recovery would take time.
"We were told it was going to take months for [the leg] to start coming back, and it did," McBriar said. "It took until the summer before I could finally start moving again like I was before. But the prognosis is great. I talk constantly with Dr. Spinner. He's really thrilled with the progress I've made over the last months."
When he signed with the Eagles in late July, McBriar still was wearing a brace on the foot and didn't have all of his strength and balance back. Slowly, but surely, it is returning. He wore the brace in the Eagles' first preseason game against the Steelers, but hasn't worn it since.
"It's getting better," he said. "It's just a matter of retraining muscles that haven't been functioning for quite some time.
"I'm just thrilled to be here and having the opportunity to compete for a job. It's really all I can ask for."
McBriar admitted he was pleasantly surprised when the Eagles called and invited him for a workout. He said he "sort of had my head set on midseason," as far as a possible return.
"I didn't do a whole lot of kicking before I got here," he said.
"But I feel pretty confident in what I can do now. My foot's almost back to where it used to be, and my kicking's getting there as well.
"I think I'm kicking at full tilt. My foot's not quite there yet. My balance is still a little bit shaky. But it keeps progressing every week."
Before the injury, McBriar was one of the league's top punters. His 45.3-yard career average is sixth among active punters. Between 2006 and 2010, he averaged 47.2 yards per attempt.
Last year, the Eagles signed Henry, who was considered the top college punter in the country at the University of Florida, as an undrafted free agent and didn't bring in anyone to compete for the job with him.
He had an inconsistent year and finished 25th in the league in gross average (42.9) and 27th in net average (36.9). His 10 touchbacks were the second most in the league, and his 19 punts inside the 20 were the sixth fewest.
The Eagles still think Henry will be a very good NFL punter, but two-time Pro Bowlers with 45.3-yard career averages don't come along every day.
"It's been good for me to have competition the whole way through," said McBriar. "I believe it has brought out the best in what I can do."
McBriar has outpunted Henry in the first three preseason games. He's averaging 45.5 yards per attempt to Henry's 37.6, though a big reason Henry's average is so low is that several of his attempts were from the opponent's side of the 50. Henry has put five of his eight attempts inside the 20, compared to just two for McBriar.
A key in determining which punter the Eagles keep could come down to which of the two kickers Alex Henery is more comfortable with as his holder. McBriar was the holder on Henery's 41-yard miss Friday night against Cleveland.
Special teams coordinator Bobby April said holding for Henery will "definitely be a factor" in the competition between Henry and McBriar. Henry was Henery's holder last season when the rookie converted 24 of 27 field goal attempts.
"This is the first time I've worked with a different snapper in a while," McBriar said, referring to the Eagles' Jon Dorenbos. "I had the same snapper in Dallas basically my whole career there. It's just a matter of getting familiar with Jon's snapping. I believe Alex is pretty comfortable with either of us holding."
If the Eagles do end up releasing McBriar, he won't be out of a job very long. Now that he has recovered from his leg problem, there will be a number of teams interested in him.
Contact Paul Domowitch at firstname.lastname@example.org. Follow him on Twitter @Pdomo. For more Eagles coverage and opinion, read the Daily News' blog at eagletarian.com.