The 81-year-old was hospitalised earlier this week and was released a day later, reported Aceshowbiz.
"He had a mini stroke, and he is fine," said Melody, Alan's publicist.
Sources said that doctors did a battery of tests on the "Argo" actor and there was no significant damage.
He was scheduled to appear at the Los Angeles premiere of his multi-generational holiday comedy "Love the Coopers" on Thursday, but he did not show up.