I expected it to be Andy Burns, but Ryan Tepera is the one that was added to the 40-man roster to protect him from the Rule 5 draft.
Ryan turned 27 at the start of November. He pitched out of the Buffalo Bisons' bullpen in 2014. He pitched in 51 games, putting up a 3.66 ERA. In 64 innings, he allowed 66 hits, 4 home runs, with 24 walks and 67 strikeouts. He's right-handed.
Ryan was a 19th round draft pick in 2009. In 6 seasons in the minors for the Jays, he has a 4.26 ERA in 578 innings, allowed 572 hits, 215 walks and 457 strikeouts, in 167 games, 90 starts. I think he is a reliever from here on out.
MjwW took a look at the Rule 5 draft back here. He figured the Jays might add Andy Burns or John Stilson to the 40-man. The team does have several players they could have dropped from the roster to make more room.