Police would not reveal who actually made the call.
Jefferson refused Friday to discuss the incident during Utah's media day for the 2011-12 season.
"It's a personal matter and I'm done talking about it. I want to discuss basketball," Jefferson said. "I know you've got some good questions about basketball, right?"
Reporters gave Jefferson space. But Big Al did take a moment took reflect on a strong seven-year professional career that sometimes has been overshadowed by off-the-court drama.
"It's life, man. Life is full of adjustments, full of changes," Jefferson said. "It's life."
Lewis, listed in jail records as 5-foot-7 and 170 pounds, was booked into jail just before 9 p.m. Thursday.
She bailed out shortly thereafter, but missed her 10 a.m. arraignment in Holladay Justice Court, where she is charged with assault and domestic violence in the presence of a child, both class B misdemeanors.
The arraignment hearing was later rescheduled for Jan. 18 before Judge Augustus Chin. A court clerk said the hearing was reset because officials were unsure whether Lewis knew she had to appear.
Jefferson averaged a team-high 18.6 points and 9.7 rebounds during the 2010-11 season, his first with the Jazz.
While playing for Minnesota, he was arrested in February 2010 for suspicion of DWI and was suspended by the Timberwolves for two games after the incident. He accepted the suspension, apologizing to his teammates and fans.
Jazz CEO Greg Miller said the organization will "stay out of" Jefferson's latest incident and acknowledged he didn't feel qualified to comment since it involves the center's personal life.
Utah coach Tyrone Corbin said he spoke with Jefferson about the reported assault, and trusts him to do the right thing and handle his own business.
"He's done handled himself extremely well through it and it's a family matter," Corbin said. "We're proud of the way he handled things."