R Y B A N Z: Oklahoma City Thunder Notebook: James Harden suffers minor setback Read more: http://newsok.com/oklahoma-city-thunder-notebook-james-harden-suffers-m

James Harden had a rude welcome to the NBA on the opening day of his first training camp Tuesday. The No. 3 overall pick was accidentally poked in the eye by a teammate and had to leave practice near the conclusion of the session to get it treated as a precaution.

The incident was labeled minor by a team spokesman, and Harden was scheduled to play in the night session that wrapped up the first two-a-day of camp. Harden was leaving the practice court at the same time media members were allowed into the gym and wasn’t available for comment.

Thunder coach Scott Brooks said the rookie performed well in his first real NBA practice before the setback.

"James really buys into wanting to get better,” Brooks said. "He does a lot of good things, and if he continues to work on the defensive end and continues to be a playmaker, he’s going to help us get better.”

Defense dominates first day

Brooks used the majority of the opening day of training camp to practice what he’s preached since taking over last season — defense.

"We focused on the defensive end and containing the ball and doing a good job of having weak side help,” Brooks said. "We just have to continue to work on our good habits.”

More two-a-days coming

NBA rules permit teams to conduct two-a-day sessions in only the first six days of training camp, and Brooks plans on taking advantage, with two more practices scheduled for today. Teams are prohibited from contact drills in both sessions, however, so Brooks said the second sessions will be used mostly for conditioning, shooting drills and to install the offensive and defensive principles.

"I don’t know if we’re going to use all six days, but we have to put a lot of stuff in and it’s a great time of the year,” Brooks said. "Training camp is fun. Certain guys are fighting for playing time and to even make the team. ”

Collison misses practice

Nick Collison did not practice Tuesday after coming into camp with a sprained ankle that he suffered about a week ago while working out. He is listed as day-to-day.