It goes without saying that when a No. 8 seed loses one of its best players early in a first round NBA Playoffs series, it will hurt. Darren Collison left in the second quarter of Game 2 of the Indiana Pacers' upset bid against the Chicago Bulls after spraining his ankle after stepping on a baseline cameraman. The Pacers had a nine-point lead at the time; Chicago ended up winning by six as Indiana fell into turnover trouble and a down-tempo offense with Collison out.
According to data from NBA.com's Statscube tool, the Pacers have been excellent in this series when Collison is on the court. In 49 minutes with Collison on the court, the Pacers have a +6.9 efficiency differential, with a strong 109 offensive rating and very good 102 defensive rating. In 47 minutes with Collison on the bench (or in the locker room, as it were), the Pacers have an efficiency differential of -16.7. That's obviously a massive swing.
While the numbers are very obviously subject to sample size issues, note that most of Collison's minutes -- 117 of 128 -- have come with Rose also on the floor. It isn't as if the Pacers are fattening up against a Bulls B-team lineup when Collison's on the floor.