At the start of this month, he hadn't played in an NFL game.
McCann returned an interception 101 yards for a touchdown two weeks ago and followed it up by grabbing a swatted punt and returning it 97 yards for another touchdown this past weekend.
He's the first rookie ever to have touchdowns of at least 97 yards in consecutive games. According to STATS LLC, he's only the second player to do it since 1950, joining Tony Horne of the St. Louis Rams in 1999.
And then there's this: McCann has been chosen NFC player of the week after the second and third games of his career. He got the defensive version last week and Tuesday received the honor for special teams.
"It's definitely a cool feeling," he said.
The only downside to McCann's streak is that he will have to do something spectacular against the Saints on Thursday just to keep it going. He will need a kickoff or a fumble to continue the variety -- and it better be a long one.
"I can just go out and do 90-plus (and) my production is falling," he said, laughing. "I've set a high bar."
He's already hearing about his 4-yard dip.
"People are like, 'You couldn't have done 102?'" he said.
McCann's plays have been biggies in every sense.
The first turned a shaky lead into a solid one, the second put Dallas ahead for good. Together, they've helped the Cowboys go 2-0 under Garrett after being 1-7 under Wade Phillips. They've also underscored the message Garrett delivered to the club in his first address after taking over, that pedigree doesn't guarantee playing time, only performance does.
"It's what you see in practice and what you see in the games," Garrett said. "It doesn't matter where you got drafted, if you are a rookie free agent or what you were. If you are doing it, we are going to give you a chance to do it more. He has certainly been able to do that the last couple of weeks."
Speed is McCann's biggest asset.
On his pro day at SMU, in front of NFL scouts, McCann ran the 40-yard dash in 4.32 seconds going into the wind and 4.28 with the wind at his back. The lower figures matches the best time at the scouting combine, the one McCann wasn't asked to attend.
He figured it would happen because he played for a bad team and was overshadowed by another speedster on the squad. So McCann stayed in the Dallas area, working out with other folks he knew through school. He often spent afternoons running with the women's track team at SMU.
The Cowboys invited him to training camp and he played well in the preseason. Coaches told him he was good enough to be their fourth cornerback. However, management decided to keep three.
So McCann went on waivers and the Ravens claimed him. The rules required them to put him on their active roster, but then they waived him, too, in hopes he would clear and they could sign him to their practice squad. Baltimore GM Ozzie Newsome told him the club wasn't happy with their punt returners and wanted to keep him around in case they decided to try someone new.
"It was definitely something that I wasn't expecting," McCann said. "Honestly, when that happened, I had to step back and look at all my options and think about what situation was best for me."
Dallas was among several other clubs that called offering spots on their practice squads. He picked the Cowboys because of the familiarity and because they were still carrying only three cornerbacks. Sure enough, injuries hit and he was activated Nov. 4 and made his debut a few days later.
"Looking at depth, you've got to go with where you can get on the field the fastest," he said. "I felt like if it was another team, I definitely wouldn't have been the next man to step in and go in and play."
A lot of players might have been broken by this difficult path. McCann kept believing things would work out for the best.
"I definitely felt like I would have the opportunity," he said. "After going through the preseason, I felt I was good enough to play in this league. So I've never doubted myself. It was a matter of who is going to give me my shot and when is it going to come."
Now that he's gotten his shot and made the most of it, McCann is enjoying the spoils. He had about 70 text messages after his latest touchdown and over the past two weeks his following on Twitter (bmac929) has tripled. He's become such a popular subject to interview that tight end Martellus Bennett grabbed a microphone Monday and conducted one of his own.
But McCann is keeping himself grounded. As nice as the highlights are, those are just two big plays. To build a career, he need lots of solid ones.
"I got a couple of eyes on me, which is good," he said. "I do watch my film, I do lift weights, I do run and follow the lead of guys like Terence (Newman) who've been in the league and productive for a long time. I want to continue to improve."
"I hope he kicks it to me," McCann said.
Copyright 2010 by The Associated Press