Pierce turned the ankle in the first quarter of the Celtics' ugly 108-89 loss to the New York Knicks on Sunday night. Pierce stayed in the game, notching 24 points and a season-high 15 rebounds before leaving the blowout for good in the fourth quarter.
The injury does not appear to be a serious one, as Pierce said afterward that it was just "a little sore" and that it should not be much of a problem. Still, Rivers wants to make sure his star rests up and does not make the injury any worse, especially with all the issues the Celtics have had this season. Boston is already without Rajon Rondo and Jared Sullinger for the rest of the year, and both Kevin Garnett and Courtney Lee have been nursing injuries of late.
With the postseason rapidly approaching and the Celtics firmly in, resting Pierce on the second of a back-to-back a day after suffering the injury certainly seems like the right play.