"To me, when he's coming down the floor, he's very similar to LeBron James," Collins said before Wednesday night's game in Houston. "He combines size, strength and shooting, and he loves to make contact."
Harden played up to Collins' description, finishing with 33 points and seven assists to lead the Rockets to a 125-103 victory over Philadelphia.
Collins mentored Harden when he played at Arizona State and said he frequently told the young player that he had "no motor."
"(Collins) taught me a lot," Harden said. "I was too nonchalant and just chill. That's how I still am, but I have a little motor in me now. That's the difference."
Harden topped 20 points for the seventh straight game to send the 76ers to their fifth straight loss. He made a career-high 17-of-18 free throws, including six in the fourth quarter, as Houston improved to 9-2 in its last 11 home games.
"James is kind of the head of the spear," Rockets coach Kevin McHale said. "He's the guy that takes us out and gets us going."
Toney Douglas heated up in the fourth quarter for the Rockets, hitting five 3-pointers and scoring all 17 of his points.
"We just couldn't get any stops, and Harden controlled the game," Collins said. "We are just so undermanned."
Young hit a 3-pointer with less than three minutes left in the third quarter to cut Houston's lead to three, but the Rockets finished the quarter on an 8-1 run and led by 10 at the start of the fourth. Houston forward Greg Smith keyed the rally, scoring eight of his 13 points in the final two minutes of the third quarter.
"James (Harden) came up to me during a timeout and told me we needed to finish the quarter with energy," Smith said.
Chandler Parsons got the rebound on his own 3-point attempt and followed with a powerful dunk that kept Houston's lead in double digits midway through the fourth quarter. Parsons finished with nine points and was the only Rockets starter not in double-figures.
Philadelphia guard Evan Turner left the game with nine minutes left in the third quarter after suffering a left ankle injury. Turner limped to the locker room and returned with less than five minutes remaining, but he only stayed in the game for 17 seconds before heading back to the locker room.
Collins said the extent of Turner's injury was not immediately clear after the game.
Turner never re-entered the game and finished with six points, three assists and two rebounds, ending a 17-game streak of scoring in double-figures. The 2010 second overall pick has averaged 17.7 points in December and 15.5 this season.
Turner's absence might be the latest setback for the injury-plagued 76ers, who have been without center Andrew Bynum for the entire season.
Philadelphia point guard Jrue Holiday, the team's leading scorer at nearly 19 points per game, missed his fourth straight with a sprained left foot. Collins said he hoped Holiday would be back for Friday's home game against Atlanta but said the team isn't rushing his return.
"When you put a loss behind your name as a coach, they don't ask who played in the game," Collins said. "There is no asterisk that says you're undermanned."
Texas A&M quarterback and Heisman Trophy winner Johnny Manziel attended the game and received a brief ovation when his name was announced halfway through the third quarter. Texas A&M University in College Station is roughly 100 miles from Houston's Toyota Center. ... Houston F Patrick Patterson missed his third straight game with a bone bruise in his right foot.