DALLAS – O.J. Mayo kept starting over.

The post-practice shooting drill consists of five shots from each of five locations around the 3-point arc. On this afternoon, Mayo was misfiring much more often than not and allowing the frustration to get to him. He stopped the drill several times, basically hitting the reset button.

Mayo looked like a man in the process of rebuilding his confidence, which would be understandable for a former third overall pick who struggled the last two seasons after being demoted to sixth man in Memphis. That theory, however, was quickly shot down by Mayo and coach Rick Carlisle.

Mayo’s take: It was just one of those days in training camp, when his legs felt heavy and his shot wasn’t falling. As far as Mayo is concerned, his confidence is directly related to the all the time he spent working on his game this summer.

“I worked my tail off this summer,” Mayo said before the Mavs left for Europe. “Now it’s just about putting it all together.”

Those pieces didn’t quite get put together during the Mavs’ trip overseas. Mayo struggled in his first appearances in a Mavs uniform, scoring only nine points on 2-of-13 shooting in a total of 50 minutes against Alba Berlin and FC Barcelona Regal.

It’s way too early to jump to any conclusions, but it wasn’t an encouraging start for the shooting guard the Mavs are counting on to fill Jason Terry’s shoes as Dirk Nowitzki’s scoring sidekick.

That’s a challenge that Mayo relishes. His work ethic since he signed with the Mavericks cannot be questioned.

He made the move to Dallas a couple of months ago because he wanted to spend as much time as possible working with Carlisle, who tinkered with the mechanics of Mayo’s shot. Mayo is typically one of the last Mavs off the practice floor along with Rodrigue Beaubois.

Mayo has ample reason to be motivated. He wants to get paid after settling for a one-year, $4 million deal with a player option for next season that would only be exercised if things don’t go as planned. He wants to live up to his potential as a former third overall pick whose numbers declined after an All-Rookie campaign. And he wants to win.

“It’s a new opportunity for me,” Mayo said. “At the same time, it’s a top-tier organization in Dallas. A lot of great players come through here and are successful. You just don’t want to break the trend. You want to come in, play hard, play to win and continue to have a winning atmosphere here.”

To have any confidence in the winning atmosphere continuing, the Mavs need Mayo to shoot the ball much better than he did in Europe.