OKLAHOMA CITY — The Boston Celtics and Oklahoma City Thunder weren’t content with just being top-tier playoff contenders, swapping starters Thursday in a surprising deadline deal.

The Celtics sought a throwback to their style of play during their 2008 championship run, sending center Kendrick Perkins to Oklahoma City and acquiring forward Jeff Green and center Nenad Krstic.

“I’m just as surprised as everyone else was,’’ said LeBron James, whose Miami Heat started the day tied with Boston for the best record in the Eastern Conference.

The Celtics also dealt three-time slam dunk champion Nate Robinson to the Thunder and received a 2012 first-round draft pick and cash in the deal that was approved by the NBA about five hours after the trade deadline. The draft pick was previously owned by the Los Angeles Clippers.