Making his third and final planned Cup appearance of the season in a Rick Ware Racing Ford Mustang after taking in the Circuit of the Americas rounds and the Chicago road course, Button started 31st in the 39-car field and endured an eventful race to finish a lap down on winner Michael McDowell.
The Briton admitted to making mistakes after having to serve a pitlane speeding penalty and another for overshooting the first corner while chasing Kevin Harvick. He also lost time being turned around by Ricky Stenhouse Jr.
But despite the "disappointing result", in setting the sixth fastest race lap Button said his pace was "really good" and came away satisfied with his improvement over the weekend.
"The pace is there, it’s just that I made mistakes today," said the 15-time F1 race-winner.
"The car was working well. Yesterday was frustrating just because we didn’t have any pace. Today, the guys did a really good job of finding a set-up that worked for me.
"I could brake later, so I could make a lot of moves. I can’t imagine how many cars I actually overtook during the race.
"But at the end of the first pitstop, I was speeding into the pitlane. So, I had to do a drive-through. Kills your race – about 30 seconds in pitlane.
Source: Autosport