The move comes a day after Golden State announced that Durant will be sidelined indefinitely.
The move comes a day after Golden State announced that Durant, the 2014 NBA Most Valuable Player who joined the Warriors last July, will be sidelined indefinitely after suffering a sprained left knee ligament and bone bruise.
Durant will be re-evaluated in a month and could return for the final games of the season as the Warriors, who own the NBA's best record at 50-10 and are 3 1/2 games ahead of San Antonio in the race for the top regular-season record and home-court advantage throughout the NBA playoffs that begin in mid-April.
Durant averages team highs of 25.3 points and 8.2 rebounds plus 4.8 assists for the Warriors.
Helping to fill the void will be Barnes, who previously played for Golden State from 2006-2008.
Barnes averaged 7.6 points, 5.5 rebounds and 2.8 assists over 54 games this season with the Sacramento Kings before being released.
Barnes has career averages of 8.2 points, 4.6 rebounds and 1.8 assists over 909 games with the Los Angeles Clippers, New York Knicks, Philadelphia 76ers, Phoenix Suns, Orlando Magic, Los Angeles Lakers, Memphis Grizzlies, Kings and Warriors.
In 2008, as part of the Warriors' only playoff appearance between 1994 and 2013, Barnes helped Golden State upset Dallas in the opening round of the NBA playoffs.
Barnes has appeared in the playoffs in each of the past seven seasons, averaging 7.6 points, 4.6 rebounds and 1.5 assists.