WALTHAM — As the team was going through an open practice Tuesday in front of special guests and reporters, Doc Rivers spotted Jeff Green on the wing, and then cutting late to the basket.

The pass from Brandon Bass went out of bounds, hitting Rivers in the leg.

“Come on, Jeff!” Rivers shouted.

On the next possession down the court, Rivers stopped Green, who was playing defense and had a chat with him.

Rivers explained to him that Bass passed the ball to Green because Green was late cutting to the basket. Bass thought that’s where Green was supposed to be, messing up the whole set.

“We need you to be better,” Rivers told him.

After practice, Rivers reiterated that Green, who is 8.3 points in his first three games, can be great – but only if he expects to be great.

“Jeff is important to us, not [just] for this year but for long term. I’m hard on Jeff,” Rivers said, clearly referring to the $36 million investment through the 2015-16 season.

Then Rivers thought pattern changed on the fly, almost as if he was catching himself lowering expectations of the swingman who was just given a four-year commitment from the team after proving himself healthy after heart surgery last January.

“I don’t actually think I’m hard on him. I think I’m fair on him,” Rivers said. “I think he’s hard on me. So, we’re going to demand out of him this year to be great because I think he has the ability to be great.”