Title says it all. I would prefer something close to the Toronto Rehabilitation Institute, which is here, Google Maps
Here’s a few options. Mercatto and the Queen & Beaver would be the closest to where you’ll be.
Try Cafe Crepe, 246 Queen St. West http://www.cafecrepe.com/index.html
Awesome paninis (the proscuitto, tomato, bocconcini is so good) and the sweet smell of fresh crepes!
Or Burrito Boyz, 218 Adelaide St W http://www.burritoboyz.ca/
Don’t let the awful flash site discourage you - these are some tasty burritos.
Queen Mother, 208 Queen St. West has good variety and is more sit-down than BB above http://www.queenmothercafe.ca/index.html
You’ll be on “hospital row” so there are other sandwich shops / street meat vendors closer to the Rehab center if you’re low on time. Lots of Asian restaurants in and around Dundas there too. I’m curious to know what you end up eating 
Unfortunately, I got into a fender bender in the cab from the airport to the meeting. We were behind a semi when it decided to back up into the cab. Then the truck driver had the gall to say it was the cabbie’s fault.
Needless to say, this put us behind and I never had a chance to eat at the wonderful suggestions made (thank you). Maybe next time.