Lowrie had already been scheduled to play at Lowell, simply because of weather issues at Double-A Portland.
Without optioning Lowrie, the Red Sox would have been forced to activate him by Saturday.
But thanks in large part to getting hit in the knee by a pitch on June 23, Lowrie isn't quite ready to rejoin the Sox.
Coming off left wrist surgery, Lowrie has been using his rehab assignment similar to a Spring Training.
For the rest of Lowrie's stay in the Minor Leagues, the Red Sox can move him between affiliates to minimize the travel.
The option means that he needs to spend a minimum of 10 days in the Minor Leagues before being activated by the Sox.
Lowrie will first be eligible to play for Boston on July 18, the second game after the All-Star break.
Nick Green has been starting the bulk of games for the Red Sox at shortstop, with Julio Lugo getting spot starts.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.