Pistons forward Charlie Villanueva knows his team is struggling making 3-pointers. That is his skill-set, and he wants to help. But he said he remains two days away from practicing with the team as he recovers from a sore right shoulder. He said he has a tough time lifting his arm over his head and following through. He works out daily with trainer Arnie Kander, but is hopeful of practicing by the weekend. “Of course it’s frustrating being in a suit and not being able to help this team knowing they need some shooting out there,” Villanueva said. “I can definitely provide that. It’s frustrating, but at the same time I don’t want to go out there being in a hurry and not being able to help the team because I am not 100 percent.” The Pistons are one of the worst three-point-shooting teams in the NBA, hitting just 27.7 percent of their shots heading into Friday’s game against Oklahoma City at The Palace. Villanueva is a career 34.6 percent three-point shooter and averaged double-figure scoring his first six years in the league. However, he has averaged just 7.0 and 6.8 points per game his last two seasons with the Pistons. He shot a career-high 38.7 percent from the three-point line in 2010-11, but those numbers fell to 33.3 and 34.6 percent the last two seasons.