This comes after Derek Jeter suffered a similar injury, straining his quadricep after eight innings in his 2013 debut.
Rodriguez is recovering from his second hip surgery and has been rehabilitating in the minor league for Scranton/Wilkes-Barre, and has not yet played for the Yankees this season.
On Sunday, Rodriguez underwent an MRI that revealed the Grade 1 strain. Rodriguez remains on the disabled list but has exhausted the maximum allowable days of minor-league rehabilitation.
The Yankees will have to petition for additional rehab time, and do not know when Rodriguez will be able to play again. In the meantime, the 37-year-old will return to the team's training complex in Tampa for rest and treatment.
Amid his injury comes a potential suspension from a Biogenesis scandal and rumblings of a related conspiracy.
Rodriguez insisted Sunday that he was ready to make his season debut, and received the MRI just hours later. Columnist Bob Nightengale said that the Yankees may be sidelining Rodriguez long enough for the Biogenesis findings to be revealed, ensuring that Rodriguez does not play while Bud Selig is commissioner.
With that time out of the league, it is unlikely Rodriguez would ever play major-league baseball again, and the Yankees would be able to collect their insurance money.
Rodriguez turns 38 this week, and with a string of injuries, he may not last very much longer. With his quad injury and pending Biogenesis findings, he may never get a chance to start playing again.