The Cavaliers signed Jack to a four-year, $25 million contract over the offseason to provide some stability and veteran leadership in the backcourt.
Injuries come as a rarity for Jack. Since being drafted by the Nuggets in the 2005 NBA Draft, Jack has appeared in 611 games -- good for the seventh-most regular season games of any player during the same time period. Over his career, he has only played fewer than 79 regular season games in a season once (excluding the recent strike-shortened season).
As Fear the Sword reports, Jack's injury doesn't sound too serious, and with preseason just beginning, the team appears to be overly cautious to make sure he is ready for the regular season. This goes both ways, however, as missing out on preseason games gives less time for Jack to pick up Mike Brown's defensive system.
Through the Cavaliers' two preseason games, Jack is averaging 3.5 points and four assists in approximately 17 minutes of playing time.