JACKSONVILLE – So far, so good.

That's how Head Coach Gus Bradley has viewed the week of practice as the Jaguars prepare for the San Diego Chargers.

Quarterback Blake Bortles has taken two days of first-team repetitions, and there have been two defensive lineup changes, but mostly Bradley said he likes the focus. In the wake of three one-sided losses to start the season, Bradley said he asked for a little extra.

He said that included extra film work, extra effort, extra finish and basically "all those things that we need to do."

And he said so far this week, players have given it.

"I was really pleased," Bradley said as the Jaguars (0-3) prepared to play the San Diego Chargers (2-1) at Qualcomm Stadium in San Diego, California, Sunday at 4:05 p.m.

"It's a challenge for our guys because some of them are learning what their responsibilities are fully within the scheme. It's not about being someone they're not, it's just about challenging themselves to get better."

Bradley said both Wednesday and Thursday practices reflected that.

"It carried over today," he said Thursday. "I thought it was an excellent practice where guys competed throughout so we had a good couple of days."

The Jaguars enter the final few days of preparation for San Diego relatively healthy, with the tight end position one area of concern. Veteran Marcedes Lewis is on the injured reserve/designated to return list, and is out at least until late November. While Mickey Shuler has missed practice each day with an illness, tight end Clay Harbor has practiced full each of the last two days.

Harbor, a veteran who is the Jaguars' top move/receiving tight end when healthy, has been out since early in training camp with a calf injury.

"Clay has been doing pretty good," Bradley said. "He's had a good week and he's been feeling really good. That's a big uplift for us that he is capable of playing. He took a lot of reps, his wind is back and he feels good. To have him back has been really good for us."

Harbor caught passes for 292 yards and two touchdowns in 16 games for the Jaguars last season. Other than Lewis, Jaguars tight ends have caught one pass for eight yards this season, with that catch coming from Marcel Jensen last week.

The concern with Harbor entering the week was how he would respond Thursday after his first full day of work Wednesday. Bradley said he spoke to Harbor Thursday, when Harbor worked full.

"He said it felt good," Bradley said.

Bradley on Thursday afternoon also said Bortles has had a solid two days of practice working with the first team for the first time. Bortles got his first regular-season playing time last season against Indianapolis, and Bradley named the No. 3 overall selection in the 2014 NFL Draft the starter shortly after that game.

Bortles previously had taken two repetitions with the first team in practice during the regular season, but is taking all first-team repetitions as the starter this week.

"He's still learning out there and he did some really good things," Bradley said. "Then some things, it's almost like a game, he wished he would have had back. … You can see if he makes a mistake he picks up on it real quick. He knows it before it happens and that's good because we'd rather have it happen in practice."

Also around the Jaguars Thursday:

*Jaguars wide receiver Marqise Lee missed a second consecutive day of practice with a hamstring injury. He missed the Indianapolis game and is not expected to play Sunday.

*Linebacker Geno Hayes missed practice with a veteran day off. Defensive tackle Roy Miller missed practice and though he is listed with an ankle injury, the reason for the absence was to give him a veteran day off. …

*Fullback Will Ta'ufo'ou missed a second consecutive practice with an ankle injury. He likely will try to practice Friday. Practice squad fullback Eric Kettani is an option Sunday if Ta'ufo'ou if can't play. …

*Cornerback Alan Ball (abdomen), running back Toby Gerhart (ankle) and offensive tackle Austin Pasztor (hand) all practiced full. Pasztor continues to work with a club on his hand in practice, and his status for Sunday remains uncertain. …

*Wide receiver Allen Hurns returned to full status Thursday after working limited with an ankle injury Wednesday. He played through the ankle issue last Sunday.

*Middle linebacker Paul Posluszny practiced full Thursday after missing Wednesday with an ankle injury. He said Thursday he expects to play Sunday. …

*Jaguars defensive coordinator Bob Babich on Thursday discussed inserting four-year veteran J.T. Thomas into the starting Otto linebacker position over LaRoy Reynolds: "J.T. has done a really good job along with playing in the preseason and when he had an opportunity to get in games. He's practiced really well too and he's done really well on special teams, so that's the reason we felt like he deserved a shot and he's done a good job."…

*Babich said safety Sherrod Martin is ready to play if needed Sunday. Martin, a five-year veteran, spent the offseason, training camp and preseason with the team before being released following the final preseason game. He is the backup free safety behind Josh Evans this week. "Veterans have the ability to handle those types of things," Babich said. "We haven't changed the scheme at all and he is very familiar with that so we would be very comfortable with that." …

*Of Evans, who – like Thomas – took over as the starter this week, Babich said: "Josh is really comfortable with the position he is in and it allows him to play fast." Evans started 11 games at free safety last season. He is replacing Winston Guy in the lineup this week. …

*Wide receiver Cecil Shorts III, asked Wednesday if he thought rookie quarterback Blake Bortles was ready for his first NFL start: "Absolutely. Bortles Kombat … Bortles Kombat … It's going to be a lot of fun out there with him. He brings a lot of excitement to the game. He has the ability to extend the play. He takes chances, gets the ball out of his hands quick and does a good job back there." …