The Blue Jays could promote from within
This option feels like the most unlikely one on the list, but it's one that needs to be brought up. With many middle infielders down in the minors, the Blue Jays could very easily promote somebody instead of making a big trade and losing assets.
Down in the minors, Ernie Clement, Leo Jimenez, Addison Barger, Orelvis Martinez and Otto Lopez are all on the 40-man roster and could all conceivably be promoted. Martinez is by far the youngest and was only just promoted to Triple-A, so him moving up to the big leagues already feels like a long-shot, so we'll focus on the others.
Each of Clement, Jimenez, Barger and Lopez are on hand in Triple-A alongside Martinez. Most of these names have been floated in recent trade rumors because, well, the Blue Jays have too many middle infielders on the farm. Jimenez and Lopez are both defensive-first players who don't have a direct path to the big leagues while Clement and Barger both have more thump in their bats.
With Barger and Lopez both being outfield-capable as well, the Blue Jays have been mixing and matching their minor leaguers on defense in an effort to get everyone playing time. Clement has also had multiple stints in the big leagues this season and he can play shortstop at a decent rate, so he would be the top option to get the call if the Jays elect to promote from within.