The third-year guard, who starred in his first two NBA starts, pledged to give Boston's starting point guard job back to its rightful owner -- Kyrie Irving.
"Kyrie's probably one of my biggest supporters outside of my family through this little process," Rozier said after the game. "So I know he's happy for me. And when he comes back he's going to pick it up."
Irving has missed the last two games with a bruised quad and is doubtful for Sunday's home matchup against the Portland Trail Blazers -- a game being played some six hours before another local team chases another Super Bowl title.
Rozier, always a spark plug off the bench, on Wednesday became the first player -- since Basketball Reference began tracking starting lineups in 1970 -- with a triple-double in regulation time in his first pro start. He had 17 points, 11 rebounds and 10 assists, and the triple-double also matched Irving's career total in 429 games.
Then came Friday night's explosion in a game where rookie Jayson Tatum also had a career high with 27 points.
In the two games, Rozier had 48 points, 18 rebounds and 12 assists, shot 53 percent from the floor and 64 percent from 3-point range, and was a plus-63.
"He's come a long way," teammate Al Horford said. "I was always just impressed by his ability, but you don't know if that's going to translate. For him, the more that we've played him, doesn't matter the positions we put him in, he just keeps learning and growing and he's playing the right way.
"He's playing aggressive, but what I like most about him is that he really commits on the defensive end, rebounds great. I've just been very happy to see his progress and I know that he's going to continue to get better."
Irving's status was up in the air for Sunday, but was one of several roster questions for the Celtics (38-15 with three straight wins) as they face a team that had been hot before yielding 130 points in a loss Friday night at Toronto.
The Celtics signed free-agent big man Greg Monroe on Friday and his availability for Sunday was not known as he completed the waiver process. Marcus Morris (hip) and Shane Larkin (knee) were also injured with status unknown.
Marcus Smart is out with a lacerated hand. And a report surfaced Saturday that he could be moved, with the intended compensation a first-round draft pick.
Regardless of who the Celtics have available for this game, especially in the backcourt, they'll have to deal with the outstanding Portland guard combo of Damian Lillard and CJ McCollum.
On Friday night, Lillard reached 10,000 points faster than any Trail Blazers player in franchise history and also became the eighth NBA player with 10,000 points and 2,500 assists in his first six seasons. The others are Michael Jordan, LeBron James, Larry Bird, Nate Archibald, Pete Maravich, Dave Bing and Oscar Robertson.
"It's a quite a list," coach Terry Stotts said. "All Hall of Famers except for LeBron, and I think he has a chance to get in, too."
Said Lillard: "It's something I'm really happy about. Now I've just got to keep on moving up."
The milestone came a game after McCollum joined Lillard (three times, including a franchise-high 59 this past April) and five others in Portland's 50-point club. He dropped 50 in three quarters against the Chicago Bulls.
The Blazers, who had a four-game winning streak snapped Friday, have won seven of their last eight -- but are 2-5 in their last seven road games.
Former Celtics player Evan Turner (left calf soreness) is probable for Sunday and Shabazz Napier (left big toe soreness) is questionable.
Each team won on the other's floor last year and this is a series that once saw Portland (29-23) win nine straight games at TD Garden.