Thunder guard Russell Westbrook to miss first month of season

When the Oklahoma City Thunder start the season at the end of the month, they'll be doing it without starting guard Russell Westbrook.

The Thunder announced Tuesday that Westbrook underwent successful arthroscopic knee surgery earlier in the day. Thunder Executive Vice President and General Manager Sam Presti said Westbrook had some swelling that forced the surgery.

"Russell has been incredible in his work and rehabilitation. He has been pain-free and has performed at a high level during practice, but has experienced recent swelling that had not subsided," said Presti.

Presti said the medical team determined a stitch had become loose, causing the swelling, but the meniscus that Westbrook originally tore has healed properly.

Westbrook tore the meniscus when he collided with Patrick Beverley in the first round of the playoffs in May against the Houston Rockets.

Presti said Westbrook will miss the first 4-6 weeks of the regular season.