Who is this Jimenez?
Aj Jimenez is a 25-year old former 9th round pick (2008) who has yet to play a day in the big leagues. He's out of options so would come extremely cheap. Career .272/.314/.381 hitter in 8 minor league seasons, including .247/.292/.339 in 89 games at AAA. Missed quite a bit of time over the years with injuries, including TJS.
Don't know his defensive rep* (though he does have a career CS rate of 40%) but at first glance he doesn't seem to be a tremendous upgrade over the internal options.
*Further checking indicates Baseball America named him best defensive catcher in Toronto's system for at least three years in a row (after the 2011, 2012 and 2013 seasons).