When will Alex Rodriguez return to the Yankees?

After Alex Rodriguez was scratched from the last game of his minor league rehab due to injury, he will have an MRI on his left quadriceps. He reached the 20 day limit of his rehab and now must go either to the disabled list or the majors. This is a big blow to a Yankee team that is currently 4th in the AL East and 6 games out of first place.