3 biggest free-agent mistakes in Boston Celtics history

The Boston Celtics have had tons of success in their history but it hasn’t always been rosy and they’ve made their fair share of free-agent mistakes.
The Boston Celtics have had a very clean history when it has came to NBA off-season moves, but, like every other team, they’ve made some mistakes.
A horrible signing during the Kevin Garnett, Paul Pierce, and Ray Allen era forced the team to have less of a chance to repeat after 2008. Another mistake was made during the very horrible Rick Pitino era. Additionally, in recent years, they have made a major mistake in free agency which they were only able to get over by making an amazing trade.
Celtics biggest free agent mistakes: 3. Chris Mills
Under Pitino, the Celtics signed Chris Mills to a seven-year deal worth around $33 million (again this is a pre-cap jump so a pretty big investment). The Celtics would end up trading Mills not even three months into the deal to the New York Knicks. In order to get Mills, the Celtics traded away two second-round picks and Eric Williams to clear cap space.
Williams was on his rookie contract which would have made him a cheaper investment. In terms of total disaster, this would not have a huge long-term impact due to the fact that the Celtics traded him away. Still, this signing represented the Rick Pitino era in a nutshell.