The Oklahoma City Thunder announced Thursday that power forward Patrick Patterson underwent successful arthroscopic surgery on his left knee.

General manager Sam Presti indicated in the release that it was a "proactive procedure" to ensure there isn't structural damage in Patterson's knee or anything that could hamper him long term.

Patterson's health will be re-evaluated in four-to-six weeks, which could cut close to training camp beginning Sept. 26.

The 28-year-old Kentucky alumnus signed with the Thunder in free agency earlier this offseason on a three-year contract reportedly worth $16.4 million. Many were surprised that Patterson didn't fetch more on the open market, and it seems the lingering injury - he tweaked his knee late last December - can help explain the below-market deal.

Patterson had hinted to something significant happening Thursday:

He has career averages of 7.9 points, 4.7 rebounds, and 1.2 assists over seven seasons. He spent the last three-plus years with the Toronto Raptors, and missed a handful of games in 2016-17 due to knee injuries.