FOXBORO -- Some things have changed since the Patriots and Bills played in Week 4.
For the Bills, their offensive line lost left tackle Cordy Glenn for four games with an ankle injury, then got him back last week against the Texans. They also lost starting right tackle Erik Pears to season-ending injured reserve, and Chris Hairston has come on to replace him.
The Patriots defensive line hasn't undergone those kinds of personnel changes, but New England's two defensive ends have changed in that their understanding of their position has grown since their matchup with Buffalo six weeks ago.
Rookie Chandler Jones was just getting his feet wet in the NFL back then. And Rob Ninkovich, who has spent most of his seven-year career as a linebacker, was still learning the intricacies of being an end.
Ninkovich had a sack and a forced fumble against the Bills in their first meeting. He remembers that game as one of the turning points to his season.
"I think it was just getting comfortable with my position," said Ninkovich, who has 2.5 sacks and three forced fumbles since then. "Knowing these are my responsibilities and just doing them the best that I can for my position and for my job . . . I was able to put my hand down and just go. Get to the ball carrier. Wherever the ball is, my was job to get there. Just having that never-stop high-motor mentality."
Ninkovich went up against Pears for most of that afternoon in Buffalo. Now he'll get a crack at Hairston.
Hairston replaced Glenn during the Patriots game in Week 4 when Glenn left injured in the third quarter. In Ninkovich's preparation for this week, he studied how Hairston handled Jones that day.
Jones will be matched up with Glenn, also a rookie, once again. The Patriots young sack leader said he's never played the same opponent twice in his career -- including high school and college. He's looking forward to using the knowledge he acquired in Week 4 to his advantage on Sunday.
"When you play a team twice," Jones said, "I feel like, you have personal notes, and I have personal notes, and I'll look over them again. Definitely."
Jones got by Glenn for a sack in their first meeting. Despite all that's changed since then, he's hoping for more of the same this weekend.
"Cordy Glenn is a great left tackle," Jones said. "Watching him week in and week out. He was out for a little bit with an injury, but he's came back strong. He's a good player. It's my job to get after him."