Milicic purportedly turned down $6 million over three years with Spanish club Real Madrid in hopes of remaining in the NBA. The Celtics already have a packed front court: Kevin Garnett, Brandon Bass plus first-round draft picks in Jared Sullinger and Fab Melo and backups in Jason Collins and Chris Wilcox. The team has 15 guaranteed contracts, so they would have to release somebody (likely Wilcox, who the team released from a larger guaranteed contract earlier in the year when he was revealed to have a heart irregularity). It's not clear whether the Celtics intend to cut somebody and eat their guaranteed money for Milicic, but if this story is to be believed, that's what they'll have to do. Milicic would certainly seem likely to want something more than a training camp invite if he turned down millions to play in Europe.
Milicic is obviously most famous for being a bust as the No. 2 pick in the 2003 NBA Draft, but he turned himself into a reasonably dependable backup center, averaging at least eight points and five rebounds in 2009-2010 and 2010-2011. Those numbers saw a dropoff this past season, leading the Minnesota Timberwolves to amnesty the $10 million remaining on his deal this offseason. In nine NBA seasons, he's averaging 6.0 points and 4.2 rebounds.