FOXBORO -- When Devin McCourty suffered a concussion in the third quarter against the Ravens last week, rookie safety Duron Harmon was ready to step in. He had been forced into spot duty once before on Nov. 3 when veteran safety Steve Gregory broke his thumb in the first half of a 55-31 win over the Steelers and was not rattled by his sudden insertion.
"It's definitely a lot easier than what it was the first time," Harmon said of last week's call to action. "I know at any time I could be in there and I just take things from what happened earlier in the season when I had to come in and spot play and just try to see what helped me then and what wasn't helping me."
With the help of both Gregory and McCourty, two veterans with good understandings of Patriots schemes, Harmon has developed into a reliable player at the back end of the Patriots defense.
He finished with three tackles last week and helped the Patriots keep the Ravens at bay by playing in 48 of 73 snaps, according to ESPNBoston.com's Mike Reiss -- no small feat considering Baltimore quarterback Joe Flacco has consistently tested opposing safeties all year with long pass attempts.
Given that McCourty did not participate in Patriots practices on either Wednesday or Thursday of this week, there is a chance Harmon is once again given a starting role. While Gregory was injured, Harmon was a regular in the secondary, seeing significant time against the Panthers, Broncos (against whom he played all 90 defensive snaps) and Texans.
"I had to grow up a little faster than some rookies," Harmon said. "I've been put in positions to play a lot and try to help our team win. All I can do is just be appreciative from that experience and just learning from everything. The good, the bad and the not-so-good and not-so-bad."
The third-round pick out of Rutgers hasn't had as many big plays as his college teammate Logan Ryan (also a 2013 third rounder), who has five interceptions this season, two of which came in Baltimore. But Harmon does have two picks of his own and has been trusted with New England's last line of defense on many occasions this season.
To his credit, Harmon has earned that trust by being well-prepared. Bill Belichick explained on Tuesday that the way the Patriots defense works, all safeties have to know how to play what's traditionally been recognized as the "strong" and "free" safety spots.
Whether a player is on the left side or right side of the defense, he has to know how his responsibilities will change with the look provided by the opposing offense.
"I think the way it’s going now in the NFL," Belichick said. "The teams do so much formationing and if they see that you have a pattern, that you want to be strong and free, then they just make you go the other way. They move the tight end or they put you in the slot. However they do it – however you do it, then they figure out a way to make you do it the other way around.
"We’ve gone from day one kind of teaching them left and right and then we flip them so that you play right and left but if you’re playing left and right, you’re playing strong and free and so there’s an interchangeability there.
"Sometimes in a game, we might have one guy do a little more of the other but we can’t count on that. We can’t count on, ‘Well, this guy is going to be doing this and that guy is going to be doing that,’ because if they did different formations, we’d have to make some kind of adjustment. Sometimes if you check a defense, you go from one thing to another, well you’re in one thing and then if you check it, I don’t want to say out of position but you have to flip responsibilities. I think those guys are all comfortable with that. They’ve done each other’s jobs . . . It may turn out with one guy doing a little more of one thing than another, but in the end they have to be able to do both. I think they’re comfortable with that, I think we’re comfortable with that."
As Harmon prepares for the final regular-season game of his rookie year, he explained that the road from Draft Day to Week 17 has flown by in large part because he has been forced to learn so much so quickly.
"To tell you the truth, it feels like it was just yesterday," Harmon said of the start of the season. "It's been going by really fast. I've been making strides. I feel like each and every week, I'm learning new things, getting more experienced and I'm getting better. And that's the biggest thing, just keep progressing, keep getting better."