FORT WORTH, Texas -- If Saturday's final practice for the AAA Texas 500 was any indication, Denny Hamlin may be looking for a little help from Kyle Busch during Sunday's race at Texas Motor Speedway.

Busch said he will be willing to give it -- to a point. Even though they are teammates at Joe Gibbs Racing and Hamlin remains squarely in the Chase hunt, Busch admitted there are limits to what he will be willing to do.

“

I think it's great for Joe Gibbs Racing and having a shot and having a car that's capable of winning the championship, but much more than that it doesn't matter to me.

”

-- KYLE BUSCH

"I think it's great for Joe Gibbs Racing and having a shot and having a car that's capable of winning the championship, but much more than that it doesn't matter to me," Busch said.

Busch topped Saturday's Happy Hour speed chart with a fast lap of 188.180 miles per hour. Busch, who won Friday's Camping World Truck Series race at TMS, also ranked at the top of the speed chart in Saturday's earlier practice with a fast lap of 189.228 mph.

But while Busch sped around the 1.5-mile track during the final practice, Hamlin and several other Chase participants struggled. Other than Kyle's older brother Kurt Busch, who was fourth-fastest (186.858 mph), the only other Chasers to register a top lap speed that ranked among the top 10 on the chart were Hendrick Motorsports teammates Jeff Gordon (ninth, 186.226 mph) and Jimmie Johnson (10th, 186.021 mph).

Four-time defending champion Johnson heads into Sunday's race with a slim 14-point lead over Hamlin in the Chase standings, with Kevin Harvick only 38 points out of first. It's the closest the standings have been with three races remaining in the season since NASCAR introduced the playoff-type, 10-race format in 2004.

Harvick and Hamlin both struggled during Saturday's two practices. Harvick was 31st on the speed chart in the first practice (184.099 mph) and improved to just 20th in Happy Hour (185.274 mph). Hamlin went backward, with his best lap in the first practice ranking 18th-fastest (185.778 mph) and falling off to 24th (185.014 mph) in Happy Hour.

Meanwhile, Kyle Busch made it clear that Saturday's morning practice times will have only so much bearing on what transpires Sunday. Saturday's first practice ended at 9:30 a.m. Central Time and the last practice ended at 11 a.m., while Sunday's race won't even start until 1 p.m.

A day earlier, the driver of JGR's No. 18 Toyota discussed the difficulty of changing track conditions at TMS.

"We're just trying to get used to the track heating up. It started real cool in the morning and real fast and then it started changing. It gets a little bit warmer, a little bit slicker -- so, more toward the conditions in which we'll race -- as it gets later in the day," Busch said.

Busch also made it clear that while he is willing to help out Hamlin in his teammate's championship quest, that good will can be extended only so far. He used the previous week as an example, when Hamlin lost the draft at Talladega and eventually fell a lap down because of it. There was a moment during that race when there was some debate -- at least briefly and internally amongst the JGR teams -- about Busch dropping back out of the draft himself to go and get Hamlin when the No. 11 Toyota was still just half a lap down.

Busch didn't, and Hamlin eventually made it back onto the lead lap and scratched out a ninth-place finish. Busch finished 25th.

"I think in the instance of last week, dropping back and going to get him when he was a half of a lap behind -- that was going to be pretty unacceptable," Busch said. "If both of us got a lap down then we were both going to be a lap down trying to fight for the 'Lucky Dog' and that would've been defeating the purpose of going to get him.

"I think we played it smart and did what we should've done and just let it play out as it will. Any other week we do as much as we can back and forth. We talk quite a bit, our crew chiefs work together really well, the communication is there. So that's all you can really do."

Rounding out the top five on the final practice speed chart Saturday were David Ragan (187.728 mph), Martin Truex Jr. (186.955 mph), the aforementioned Kurt Busch and the surprising and surging Regan Smith (186.787 mph), who is building some late-season momentum.

The other Chasers were scattered throughout the speed chart and included Carl Edwards (14th, 185.580 mph), Tony Stewart (185.376 mph), Greg Biffle (18th, 185. 344 mph), Clint Bowyer (184.546 mph), Matt Kenseth (31st, 184.106 mph) and Jeff Burton (183.530 mph).