The Celtics issued a release earlier in the day saying Stevens is visiting an ill former Butler University player in Indiana and assistant coach Jay Larranaga would run the team against Chicago, one of the Eastern Conference's best teams.
A Celtics representative confirmed the player is Andrew Smith, 25, who played for Stevens at Butler from 2009 to 2012, including the Bulldogs' Final Four appearances in 2010 and 2011. Smith was diagnosed with non-Hodgkins Lymphoma in January 2014.
"(It's) a difficult situation for coach Stevens and people close to him," said Larranaga, 40, who has no previous NBA head coaching experience. "So we told him, 'Don't worry about what's going on here. We'll try and keep the ship going straight."
Larranaga, who was informed of the news Thursday morning, isn't sure when or where Stevens will meet up with the Celtics. Boston still has stops on Sunday in Memphis and Tuesday in New York on its road trip.
"Obviously, we still need to carry out what we need to carry out," Celtics guard Evan Turner said before playing the Bulls. "We have to play the right way, come with the right intensity and play the right brand of basketball. We're not high school kids and it's like our parents are gone. We're men and we're pros, and we need to do what we need to do."
According to social media posts by Smith's family, he took a turn for the worse in early November and was readmitted to the hospital on Wednesday. The family called for prayers via Facebook and Twitter.
Given the situation, Larranaga didn't sound surprised by Stevens' decision to visit Smith.
"He makes it very clear to our players, on a day-to-day basis, that family is the most important value, the things they're able to do away from the court," Larranaga said. "I think do a great job of giving back to the community and the impact they're able to have in those areas are so much more important than what happens on the court. So it's just another example of the person he is."
Larranaga is the son of University of Miami men's basketball coach Jim Larranaga. Asked if his father had any advice before his first NBA head coaching experience, Larranaga smiled.
"I texted with my dad real quick and he told me, 'Don't talk to the refs,'" Larranaga said. "That was his word of advice."