On the Titans’ seventh play from scrimmage Friday, Patriots rookie Marte Mapu flew up from his safety position to make a tackle over the middle.

He whiffed.

Of course he did.

Mapu spent most of this summer hunting receivers and ball carriers in a red, non-contact jersey as he recovered from February surgery to fix a torn pectoral muscle. During team periods at practice, he would sprint to stop the ball and then … halt himself. He needs more live reps.

Mapu didn’t engage in full-contact drills until a week ago at Green Bay, where he participated in joint practices but sat out the preseason game. His game-day drought ended Friday in Tennessee. Over 33 defensive snaps in the Pats’ preseason finale, Mapu missed two tackles on six attempts. Over time, a 33% missed tackle rate would drop any NFL defender on the street.

But not Mapu. He’s a rookie brimming with potential and intrigue, a hybrid linebacker/safety the Patriots seem intent on shoehorning somewhere and sometime into their veteran-laden defense. Over one series Friday, Mapu bounced between strong safety, free safety and linebacker. He also played deep zone as a single-high safety, covered a deep half in two-deep coverage, the flat, short middle and tight ends in man-to-man coverage.

What comes next?

His Week 1 role remains unclear for reasons mentioned above. The Pats are stacked at safety, content with Ja’Whaun Bentley and Jahlani Tavai at off-ball linebacker, and Mapu needs to wrap up. He’ll get there.

Elsewhere, two other Patriots defenders may have forced themselves onto the roster, a young O-lineman showed out and Bailey Zappe’s bad, bizarre summer continued. Here are the Herald’s complete film observations from Friday’s loss at Tennessee:

Patriots’ Kayshon Boutte earns praise after conspicuous lack of playing time

Callahan: The Patriots’ preseason finale shouldn’t dampen a successful summer