The Patriots’ defense has been impressive this season to say the least, but former New England safety Rodney Harrison isn’t all in on them just yet.

Harrison, now an NFL analyst for NBC Sports, discussed the defensive unit on an NBC Sports conference call ahead of the Patriots’ “Sunday Night Football” matchup with the Baltimore Ravens, and noted some vulnerabilities after eight games.

“Just watching them on tape, they do have some vulnerabilities,” Harrison said, as transcribed by WEEI. “You look at them last week against Cleveland. Nick Chubb ran through them. If he doesn’t fumble the ball twice, it’s a totally different game.

“You look at the level of the competition — and I think that’s what (Bill Belichick) is kind of referring to,” Harrison added. “The first seven, eight weeks of the season, they really hadn’t played anybody. Now you get into the meat and bones of your schedule, where you have to play Baltimore, Philly, Dallas, Houston, Kansas City with a healthy Patrick Mahomes. That will really tell how great of a defense they truly are. But to put them in an all-time great category after eight weeks, after the garbage schedule they’ve faced, I mean, we could say they’re playing extremely well, but I think the next month of the season will tell what type of defense they truly have.”

His thoughts aren’t that outside the box. Yes, the Patriots’ defense has been tremendous, that much we know, but their strength of schedule has been anything but.

Sunday will present New England with its first true test.

Thumbnail photo via Zack Cox/NESN.com