The Clippers said Barnes has some swelling inside his retina, and that he is going to get some tests run soon. For now, the Clippers said Barnes has been told to get rest and that there is no timetable for his return.
"We're going to miss him," Coach Doc Rivers said.
It has been a tough season for Barnes, who is averaging 5.9 points and 3.3 rebounds in 20 minutes.
Barnes had missed three games because of a bruised right thigh.
Bullock gets playing time
With Barnes out, rookie Reggie Bullock played 12 minutes against the Timberwolves as the backup small forward.
Bullock had six points on two-for-four shooting, going two for two on three-pointers.
"I was just confident coming here knowing that Matt was out that this was my opportunity to get some minutes and just try to produce at that position," Bullock said.
Dudley still hurting
Rivers said starting small forward Jared Dudley is not able to play much more than the 26.8 minutes he averages because of a very sore right knee.
Dudley played 29 minutes against the Timberwolves and scored 11 points.
"With Jared, we're trying to limit his minutes," Rivers said. "Obviously, having Matt out makes it more difficult. But I'm going to still keep his minutes down."