(Editor's note: Updated to reflect addition of TE Dan Gronkowski.)
When looking at the current Patriots 53-man roster, there are 17 players who weren't with the team last year. Such roster turnover is commonplace in the NFL. As noted by Peter King in his "Monday Morning Quarterback" piece on SI.com, the defending champion Packers have 16 new players. For another comparison, the Ravens have 20.
New players for the Patriots in 2011:
QB Ryan Mallett
CB Ras-I Dowling
RB Stevan Ridley
CB Antwaun Molden
RB Shane Vereen
S James Ihedigbo
LS Danny Aiken
OL Brian Waters
LB A.J. Edds
LB Jeff Tarpinian
OL Nate Solder
TE Dan Gronkowski
WR Chad Ochocinco
DL Albert Haynesworth
DE Andre Carter
DE Shaun Ellis
DE Mark Anderson