It was possible due to Garnett waiving the no-trade clause, the one he had waived to become a Brooklyn Net in 2013. He had no such clause mentioned in his contract at the time of Timberwolves dealing him to Boston in 2007. However, the team waited till his giving a go-ahead years-late to be traded. Timberwolves could not have a better player in the side than Garnett, and he would remain the best player even if Andrew Wiggins led Timberwolves to win the championship on a certain day.
Garnett had never had a godfather or a promoter like Wiggins who was actively supported by president and Wolves coach Flip Saunders in Minnesota. The best group of his tenure came during the MVP year of KG in 2003-04, the season in which Wolves were badly plagued by injuries at the time of playoffs, the worst time. That was the last time, Minnesota made that stage. The deal about Garnett for the 2015 version should not be considered as an admission that Wolves made a mistake in dealing him back during 2007. Wolves got a 20-and-10 guy in the form of Al Jefferson, and it should have worked for them.
With Kevin Garnett in the team, fans would have something to cheer for as Wolves finish this season being placed at the bottom. Saunders may try to convince Garnett to continue with Timberwolves even after the expiration of his contract, and his anticipated retirement by this summer.