Lawrie went 3-for-9 with three runs and four walks in his three games for the Fisher Cats. The club has yet to announce an expected return date, but he will likely join the Blue Jays after the All-Star break.
"I have no idea," Blue Jays manager John Gibbons said when asked for a timeline.
The Blue Jays are using the rehab assignment to give Lawrie an extended look at second base. The third-year infielder has spent his entire Major League career at third base, but he was drafted as a catcher and came up through the Brewers' system as a second baseman.
Lawrie also spent some time at second during a rehab assignment earlier in the year, when he was recovering from a strained oblique muscle. At the time, general manager Alex Anthopoulos said it was just to keep the club's options open in the future.
It seems highly unlikely that the Blue Jays would move Lawrie to second base at the big league level this season, but that could change if the club acquires another player.
Edwin Encarnacion has the ability to play third, but current fill-in Maicer Izturis has more value at second base. To further complicate matters, if Toronto attempts to move Encarnacion to third on a regular basis, it would leave the team without a reliable designated hitter.
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.