Rookie J.C. Jackson holds Steelers leading receiver JuJu Smith Schuster to four catches 40 yards.

PITTSBURGH -- J.C. Jackson was admittedly excited when he learned his assignment for Week 15. The undrafted Patriots rookie was tasked with covering Pittsburgh Steelers leading receiver JuJu Smith Schuster.

When Sunday’s game started, quarterback Ben Roethlisberger didn’t wait to test the defensive back.

“Yeah, they came at me,” Jackson said. “Even on the first play, they tried to go deep.”

One positive to take away in the Patriots' 17-10 loss was the play of the secondary. Stephon Gilmore held All-Pro receiver Antonio Brown to four catches on seven targets for 49 yards. Meanwhile, Jackson put together his best game as a pro as Smith-Schuster finished with four catches on 10 targets for 40 yards.

It was a confidence booster for Jackson, who is looking more and more like the Patriots No. 2 cornerback.

“I mean, yeah, JuJu, they were talking about it all week. He’s a go-to guy. He’s a great receiver,” Jackson said. “I just had to step up. That was my guy the whole game. I just had to do what’s best for my team and not let him catch the ball, be physical with him. That’s what I did all game.”

Even when Smith-Schuster made a catch, Jackson made it difficult. With 52 seconds left in the first quarter, Smith-Schuster made a leaping grab over Jackson for 22 yards. The rookie had perfect coverage, but it still wasn't enough. At 6:06 of the second, Roethlisberger was intercepted by Duron Harmon when trying to go to Smith-Schuster, who was being covered by Jackson.

“He did great. Every week, his role has expanded,” Harmon said. “He’s been able to play lights out. Smith-Schuster’s been putting on a show all year, and for him to go out there and play the way he did, it speaks volumes on the type of player he is and the type of player he’s going to become.”

Jackson's biggest play came with 2:34 left in the contest. On third down, at the 30-yard line, Roethlisberger tied to hit Smith-Schuster in the end zone. He nearly did, but Jackson was able to knock the ball out of the receiver's hands at the last moment.

“Yeah, it was pretty physical. JuJu’s a big receiver, fast. He’s good. He’s a good player, but I am, too,” said Jackson. “He was giving me my credit, like ‘good job, man. You’re going to be good.’”

About face: When it came to the Patriots offense on Sunday, the unit was constantly taking one step forward and two steps back in their loss to Pittsburgh.

Out of the season-high 14 penalties, nine of those moved the offense back - false start (five), offensive holding (three) and an illegal formation. The holding and false start calls really hurt the Patriots in their final three drives.

Their final series, which ended in an incompletion, saw the chains moved backward twice with a false start and then a holding call after the Pats got to the 11-yard line. On the series before, it was another holding call that pushed the Patriots back when they got to the 5-yard line.

After the game, Tom Brady said an official told him they were trying to call holding penalties “tighter.”

“The referees said they are trying to call those tighter,” Brady said. “I don’t have the replay of them. So, I don’t know how tight they are. Obviously, there is holding on every play in the NFL. That’s what we do, we hold, it’s just whether you get called or not. If they are calling it, then you just have to do a little bit less of it. that’s how you block, you hold. If they are holding. We are holding. Sometimes they call them, sometimes they don’t. If they are calling them tight, then they are calling them tight.”

Trent Brown was flagged twice for holding and a false start. Marcus Cannon was flagged twice for holding and a false start. Julian Edelman was also called for a false start and an illegal formation.

On the Patriots' final three drives, they were flagged for six penalties. They didn’t score a touchdown on any of those drives.

“Some of those were some close calls,” Matthew Slater said. “Some of those were some penalties that we can handle, but we talked about it earlier in the year. We had a game we had a ton of penalties and we got away with it, but it caught up with us today.”

When asked how he thought the game was officiated, Edelman said, ““I have no comment on how it was called.”

No. 3 seed: The Patriots are no longer in control of their own density.

After losing to Pittsburgh, the Pats (9-5) fell out of the AFC’s No. 2 seed to the third spot. That one notch down means a whole lot. If the seeding stays the same, the Patriots would play on wild-card weekend while the Houston Texans (10-4) would be the No. 2 seed behind the Kansas City Chiefs (11-3).

The Patriots biggest hope is to win their two remaining games and for the Texans to lose one. Since the Pats have won the head-to-head matchup, they’d get the No. 2 seed in that scenario. Houston’s last two games are against the 6-7 Philadelphia Eagles on the road and home against the 4-10 Jacksonville Jaguars.

“We’re in a tough spot, obviously,” Slater said. “We put ourselves in a tough spot, but at the same time, we haven’t lost our belief in each other and we still have a lot to play for. There’s really no time for us to feel sorry for ourselves. We need to figure it out, keep competing, keep trying to improve because we still have a lot to play for.”

As disappointing as their current positioning is, the Patriots could still win the AFC East with a win next week. At this point, they still haven’t locked up a playoff spot. If they lose the next two games and Miami (7-7) wins both theirs, the Patriots would be out of the playoffs. In that scenario, the Dolphins would have the better in-division record.

“We’re still in the mix,” Slater said. “We can’t lose confidence in each other. We’ll figure it out.”