POSTED: Jun 25, 2015 12:29 PM ET
UPDATED: Jun 25, 2015 3:06 PM ET
The Grizzlies announced the trade Thursday, and the Thunder said shortly after they had acquired Ridnour and a conditional 2016 second-round draft pick from Charlotte for guard Jeremy Lamb.
Both deals were first reported by Yahoo Sports.
The 35-year-old Barnes averaged 10.1 points, 4 rebounds and a career-high 29.9 minutes for the Los Angeles Clippers last season. He shot 136 of 376 from 3-point range.
Barnes averaged 8.1 points, 4.5 rebounds and 1.7 assists in 779 games over 12 seasons with the Clippers, Sacramento, New York, Philadelphia, Golden State, Phoenix, Orlando and the Los Angeles Lakers.
Ridnour averaged 4 points and 2 assists for the Orlando Magic last season. The Grizzlies had acquired him Wednesday for the rights to forward Janis Timma, a second-round draft pick in 2013.
The 23-year-old Lamb played 47 games for the Thunder last season and averaged 6.3 points and 2.3 rebounds in 13.5 minutes.
"Jeremy Lamb is a quality young wing player who we believe has the talent to help our team," Hornets general manager Rich Cho said in a release Thursday. "We look forward to adding him to our rotation next season."
Lamb joins a revamped Charlotte backcourt that includes Nicolas Batum, who was acquired in a trade with Portland on Wednesday. Batum is expected to start at the two-guard for the Hornets, Cho said Wednesday night.
The Hornets made three trades already this offseason hoping to improve a team that finished last in the league in 3-point shooting.
Charlotte traded away Stephenson and Gerald Henderson. The Hornets acquired 7-foot-1, 245-pound power forward/center Hawes and Barnes as part of the Stephenson deal last week.