Oklahoma City Thunder guard Russell Westbrook ensured he will become just the second player in NBA history to average a triple-double over a whole season on Friday, something he never thought possible.

Having already guaranteed a double-figure average in points in rebounds, Westbrook's eight assists in 120-99 defeat to the Phoenix Suns was enough to guarantee he will match the feat only previous achieved by Oscar Robertson in 1961-62.

With three regular-season games remaining, the 28-year-old is averaging 31.7 points, 10.7 rebounds and 10.4 assists.

Westbrook remains one triple-double away from breaking Robertson's single-season of 41 in a season, but he sees his most recent achievement as a "blessing".

"I could never say in a million years that I would ever think that was even possible," Westbrook said, via ESPN.

"For me to do it, it's extremely a blessing. It's something that I'm honoured to be able to do, especially in this game today, at the highest level.

"It's a blessing. I'm just very thankful and happy to be able to do it."

While it may have been a truly phenomenal season for Westbrook individually, he insisted his main focus is on leading the Thunder to a successful NBA Finals.

"My main goal since I got here, especially this season, is to win a championship," he said.

"That's what my goal is. As a leader of this team, I've got to make sure this team is moving in the right direction and I'm playing the way I need to play to make sure we're playing the best basketball we need to play."