The key to the infield being successful will be the health of Josh Donaldson and Devon Travis. It looks like Donaldson is over the calf injury that kept him out at the start at camp and Travis is being worked back from his knee injury. Donaldson is entering his final arbitration year before he goes onto the free agent market in 2019, he played 155 games and was not able to replicate his offensive numbers from 2015. However there is no doubting the importance that he has on both sides of the field and should be able to drive 40 home runs and close to 110 RBIs.
Troy Tulowitzki is the second most important infielder because of the defence he provides every game. He had a slow start offensively but turned it around in the last 12 games of Spring Training with a .407 average. The question is whether he can hit above .280 for the first time in a Blue Jays uniform. He is capable of it and will need to avoid a high number of strikeouts.
Travis should be able to hit .300 if he can stay on the field, the question is whether he can be an effective lead off hitter, especially in the postseason where the Blue Jays could use a spark from him.
First base will see many moving parts with Kendrys Morales, Steve Pearce and Justin Smoak in the mix for innings there. If Morales can play well enough it will limit the appearances for Smoak especially in games against National League opponents. Morales should come close to replacing the offensive void left by Encarnacion but the Blue Jays will rely on a committee of players to help with that.