X-rays on Morris' ankle came back negative. It's the same ankle that forced Morris out of the Celtics' game Sunday at Sacramento.
"We'll see how it responds," head coach Brad Stevens said.
Morris, a former Sun, injured his right ankle when he came down on the foot of Phoenix's Troy Daniels while attempting a 3-pointer.
Daniels was called for a foul on the play, and Morris limped to the line and made all three free throws before leaving the game with the Celtics holding a 77-65 lead heading into the fourth quarter.
"It's just sore,'' Morris said. "Be out a couple of days, but nothing long term."
Morris, who came into the game averaging 13.3 points a game, had a team-high 20 points through three quarters.
The Celtics beat the Suns 102-94 for their fourth straight win.
Information from The Associated Press was used in this report.