The Celtics will add some frontcourt depth by inking the immortal Sean Williams, reports the Boston Herald: “Sean Williams, the former Boston College center who has spent the majority of his last two years moving between Austin of the NBADL and the Dallas Mavericks, is about to sign with the Celtics for the last three games of the regular season and the playoffs. [...] Though the former BC center ran into trouble in college and early in his NBA career – mainly because of marijuana-related charges that led to a suspension from the BC program – he has reportedly been on his best behavior the last two years as part of the Mavericks organization.[...] A talented shot-blocker and defender, he can play the center and power forward positions – a substantial need for the Celtics, who currently have Kevin Garnett, Greg Stiemsma and little else to defend the rim. ‘This is insurance,’ said the source. ‘He may end up not playing a minute.’”