Indianapolis - Week after week, Donald Brown has been more productive than Trent Richardson.

And each week, the 5-foot-10, 210-pound Brown's role remains the same for the Colts: He's a change-of-pace back who plays behind the more heralded Richardson on the depth chart.

Indianapolis made headlines by trading for Richardson early this season, but he hasn't found traction since leaving the Cleveland Browns. Richardson, the starter, has 96 carries for 272 yards and has caught 12 passes for 116 yards in eight games since the trade. Brown, the backup, has rushed 48 times for 293 yards and caught 15 passes for 153 yards in the same span.

Brown says he's in a zone heading into Sunday's game at Arizona. His 5.9 yards per carry is second among the top 70 running backs in the league in rush attempts this season.

"I feel good, feel confident running the ball," he said. "Mentally I'm on it. I'm down with the blocking schemes, I understand what the O-line's doing. Offensive line's doing a great job, Andrew's (Luck) getting us in the right plays and when the first person you see is a safety, that's every running back's dream."

Brown, the ex-UConn great, started the season as a backup behind Ahmad Bradshaw and Vick Ballard. When both got put on injured reserve, Brown was still stuck behind Richardson. Colts offensive coordinator Pep Hamilton said Brown has had a good attitude about the situation.

"He's consistent, he's a pro," Hamilton said. "He's never wavered one bit. He's the first guy in the building and the last guy to leave. His attitude has been great. It's been extremely positive."

Hamilton said despite Brown's success, the Colts will continue to use Brown and Richardson the same way.

"We don't plan on changing our rotation with our backs," he said. "We've always been a running back by committee bunch, so we're going to continue to do that."

Coach Chuck Pagano believes in Richardson, in part, because of his success in Cleveland. Richardson ran for 950 yards last season as a rookie out of Alabama in 2012.

"Trent's numbers are going to come," Pagano said. "He's a damn good player. He's a damn good back. He hasn't been here as long as our other guys have been here. And I'm not making any excuses for him. He won't make any excuses for himself. We're going to stay patient and he's going to have a breakout game. His numbers will increase. His numbers will come. His yards will come."

Pagano said Brown is both tough and fast.

"He's playing really well," Pagano said. "Running hard, hitting the hole, breaking tackles, yards after contact. We all know out in space, he's a dynamic guy, can take it the distance when he gets loose."

There's nothing fancy about Brown's style - he's willing to hit the hole hard and punish defenders, then he uses his speed to break out into the open.

"For whatever reason, he finds a way to create his own yards," Hamilton said. "We're excited to watch Donald continue to have that success for us running the football."

Pagano said Brown and Richardson work well in tandem. Richardson hammers away early, then Brown takes advantage of a worn down defense.

"I think it's worked out really well to this point, and it just keeps getting better and better," Pagano said. "It's a good one-two punch, if you will. Good change of pace, if you will. Both guys are more than capable, whether they're toting the rock or catching the ball out of the backfield. So I think it's been good."

Brown said he doesn't mind sharing time because ultimately, it will help the team win.

"That's the way the National Football League's taken shape," Brown said. "There's only a few teams out there that really use one back because the backs take a punishment. You need to even out the load a little bit for longevity purposes, and this is a long season. The more weapons you have, the better offense you'll be and the better team you'll be. And that's our goal."

Brown had injury problems last season, but he is thankful to be healthy this late in the season.

"I feel good, I feel good," he said. "When my number's called, just make the most of my opportunities and when you're healthy, you got to run with it."