JACKSONVILLE, Fla. - Jermey Parnell's presence is hard to miss on the football field.

At 6-foot-6 and 326 pounds, the Jaguars' starting right tackle offers an imposing frame. An NFL veteran, Parnell knows how to use his size and strength to his team's advantage.

His absence over the last three games - due to a knee injury - has been noticed. While swing tackle Josh Wells filled in as best as he could, Parnell's high level of play was hard to replicate.

Prior to suffering the knee injury in Week 9, Parnell was probably the Jaguars' most consistent lineman this season. Losing his leadership and skill along the offensive line created some issues for both the passing and running attacks.

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During the first eight games of the season, the Jaguars averaged 166.5 rushing yards per game. In the three games without Parnell, the Jaguars picked up just 121.7 rushing yards per game.

Jacksonville's offensive line allowed just 13 sacks (1.6 per game) during the eight games before Parnell went down. While Parnell was out, the team surrendered eight sacks (2.7 per game) on quarterback Blake Bortles.

The drop in production wasn't a coincidence. Parnell is a key cog on the Jaguars' offensive line.

"What I would tell you is Josh Wells has done a great job," offensive coordinator Nathaniel Hackett said Thursday.

"I mean he has really fought hard and he's done a really good job, we've won a couple of games with him in there. But you know, Parnell is our veteran [offensive] lineman, he's been there, he's done that. He's a strong guy that just has a great attitude and really brings a lot of aggressiveness and I love that guy. We've really missed him a lot."

Parnell is set to return to the lineup against the Indianapolis Colts Sunday. He will be asked to take on athletic linebackers Jabaal Sheard and John Simon.

Bortles will be counting on Parnell for protection, as he has for the last three seasons.

"He’s a guy that takes a lot of pride in being out there and playing," Bortles said Wednesday.

"I know these past couple weeks of him not being there, that’s hurt him not being able to go play. I think him, that whole group is like that. With [Brandon] Linder and Cam [Robinson] and A.J. [Cann] and Pat [Omameh] and those guys all take on that similar mindset. Always good to see that.”

Coming off a three-game absence will be a new experience for Parnell. The veteran had missed just one game with the Jaguars prior to this season. Last year, he was one of two players to take part in every snap on offense.

Week 13 will serve as the veteran's 40th start for the Jacksonville franchise.

"He's a veteran that has played a high level of football over the years," Jaguars offensive line coach Pat Flaherty said Friday. "He's a quiet leader that kind of leads by example, not by voice. He's as important as any guy up there."

Parnell's teammates are looking forward to having him back in the mix. His partner on the right side of the line, right guard A.J. Cann, acknowledged that the group looks up to the veteran.

Parnell's approach to the game and nasty attitude on the field make him an ideal role model for the younger players on the line.

"He's an important part, he's one of the leaders up front," Cann said.

"He's a veteran guy and he brings a lot of energy up front. I think we feed off him because he's a good leader and if anything is happening up front, he's telling us to calm down and let's keep it rolling, so we do enjoy having him up front."

Follow Mike Kaye on Twitter at @Mike_E_Kaye.