Billy Donovan will be back for another season with the Oklahoma City Thunder.

Donovan, who has coached the Thunder since 2015-16 and has led the franchise to an 18-10 start this season, received a contract guarantee for the final year of his deal, according to Adrian Wojnarowski of ESPN.

'The Oklahoma City Thunder have picked up the option on coach Billy Donovan's contract for the 2019-20 season, the final year on his original five-year deal, a league source told ESPN."

As Wojnarowski mentions in the article, Donovan has the fourth-best record with the same team since he was hired in 2015. The only coaches with a better winning percentage than the Thunder head coach? Gregg Popovich, Steve Kerr and Brad Stevens.

While Donovan has led the Thunder to three consecutive playoff appearances, there is no doubt that this contract guarantee came after Oklahoma City's impressive start. This is a team that started out 0-4 and had clear weaknesses when it pertained to 3-point shooting. However, the Thunder have since rebounded and have gone 18-6 ever since. They currently have the third-best record in the Western Conference and are just 1.5 games behind the first-place Denver Nuggets.

However, Woj reports that general manager Sam Presti always considered this a formality.

"Thunder executive VP and GM Sam Presti has worked closely with Donovan, whom he hired out of Florida three years ago, and considered the guaranteeing of the contract largely a formality. It is possible that a strong playoff performance could move the organization to pursue a contract extension with Donovan, but his contract is now guaranteed through next season."

Although the franchise has hit a snag in the postseason following the departure of Kevin Durant in 2016, the Thunder look like true contenders for the first time since 2015-16, when they were within a game of advancing to the NBA Finals. The Russell Westbrook-Paul George pairing looks much improved from last season, with Westbrook handling less of the ball and less of the scoring load, and George taking on more responsibility on both offense and defense.

Furthermore, the addition of backup point guard Dennis Schroder has been a huge plus as the Thunder haven't bottomed out in games that Westbrook has missed due to injury; they're 5-3 in games without Westbrook this season. 

If Donovan can lead the Thunder, back in action against the Bulls on Monday (8 p.m. ET -- watch on fuboTV with the NBA League Pass extension), to a deep playoff run for the first time in years, it would all but ensure that he receives a contract extension at the end of this season.