Thomas will play in Game 2

WALTHAM, Mass. — In any sport, the one thing a team can't prepare for is the unknown.

Last week, the Celtics were the toast of the East after outlasting the champion Cleveland Cavaliers for the top seed and home-court advantage. Then, the day before Boston's playoff opener, Isaiah Thomas' sister was killed in a car accident.

It's created a delicate balancing act. This is a team that expected to be riding a big wave of momentum. Instead, Boston lost 106-102 to Chicago in Game 1, and the possibility looms Tuesday of falling into an 0-2 hole.

But if there's a group built for such a challenge, it would seem to be this one. There's empathy in the locker room, and a coach adept at navigating rough water.

“I think the biggest thing is they really care about each other,” coach Brad Stevens said Monday. “It's really tough when he's sitting there and some of his family is back in Seattle. ... But I think the next extension of your family is who you're around every day, and your team. ... They care about one another and they support one another. That's what you hope you have in a team, but it's probably not always the case.”

Stevens said Thomas plans to play in Game 2 Tuesday night then head to Washington state to be with his family and help complete funeral arrangements.

Chyna Thomas died early Saturday in a one-car accident outside Tacoma. No funeral date is set, but Stevens said the Celtics plan to attend.

Thomas attended a film session and walk-through Monday, but did not speak with the media. Stevens said that after services for Thomas' sister, the star guard intends to rejoin the team Friday for Game 3 in Chicago. Stevens, however, stressed that all plans are up to Thomas.