The league suspended Ariza on Monday and he'll sit out Tuesday's game against Detroit.
The 6-foot-8 Ariza is Houston's second-leading scorer, averaging 17 points. He's started the Rockets' first 23 games and leads the team in minutes (38.7 per game).
The cost of a one-game suspension for Ariza, based on his season's salary of nearly $5.9 million, is $53,218.
He went 0-for-9 from the field and scored only one point before he was ejected in the third quarter of Sunday's game for swinging his arm at DeRozan's head following a steal.
"It was a heat of the moment thing," Ariza said. "I lost my cool for a second. I got my penalty and whatever I have to do, I'm just trying to move past it and move forward. I look forward to watching my team play tomorrow and then playing against Denver [on Wednesday]."
Houston coach Rick Adelman said he hasn't decided who will replace Ariza in the lineup, but he doesn't consider Tracy McGrady an option. McGrady has yet to play this season as he works his way back from offseason microfracture surgery on his left knee.
"That's something I haven't thought about," Adelman said. "Tracy's situation is what it's been."
"We'll just talk about it and see what we're going to do," Adelman said. "Just like having a guy injured for a game, guys have to step up, guys have to be ready to play."
The Rockets were joking about Ariza's ejection on Monday.
"We were calling him Manny Pacquiao and 'Golden Boy' De La Hoya," forward Shane Battier said. "You do something like that, you're open for ridicule by the other guys on your team."
Information from ESPN.com's Marc Stein and The Associated Press was used in this report.