Arroyo is expected to be available on Wednesday, when the Celtics play the Los Angeles Clippers.
"He played against us in two playoff series. He should know some of our stuff. That's the way we look at it," Boston coach Doc Rivers said. "But he's a point guard, been a point guard all his life. So I think some of the stuff, he'll pick up pretty quickly. All the nuances of things, that'll just take time."