The Jays biggest problem this season has been their weird feast or famine inconsistency. The only thing I can think of that could fix that is to fire them up with a big splash. It's what they did when they acquired Tulowitzki which fired up the team for the rest of the season.
This time they're in a much better position than they are last year, and because of Ryu they don't have to worry about pitching depth as much. Use players like Biggio and Espinal, who I like enough but they deserve more consistent playing time, and prospects like Barger and Schneider to grab some unhappy superstar with their current situation. Toss in a vet to replace whatever player is dealt at that position. I suggest Left Field is the best candidate for an upgrade. As much as I like Kiermayer, he's older and on a one year contract and Varsho hits like a CF while playing almost as well. And all around great LF who can actually hit and field would have the largest impact on the team. I would look at 3B and DH as well, but DHs tend to be a lot cheaper and Horwitz is an interesting enough prospect that I'd rather not risk losing him just to replace Belt and Chapman, although also on an expiring contract, is young enough that he could still be good for a few years if resigned (which would free up other prospects to sweeten the pot for another possible big deal). Chapman's next contract is potentially pretty scary though, so it might be worth taking a look at similar big splashes at that position. *Or at second. Forgot about Merrifield, but he's been decent enough offensively and there aren't too many superstar 2Bs around.