Some could conceivably make the argument that the rotation is a reason for concern, due to the uncertainty over the fifth starter. Certainly, Hyun Jin Ryu's first start in over a year was a disaster, while it's still tough to predict what to expect from Alek Manoah long-term.
However, even allowing for these factors, the Blue Jays' rotation is a reason why they will still contend. Consider their overall numbers, even with Ryu and Manoah added to the equation.
The Blue Jays are fifth-best in the Majors in ERA and tied-11th in batting average. They are second in strikeouts and have proven durable, with the fifth-most innings pitched.
Admittedly it doesn't all make for positive reading, highlighted by ranking just 17th in WHIP. Overall however, the Blue Jays rotation is one of the better ones in the Majors as a whole, and certainly one of the strongest in the AL specifically.
Individually speaking, Kevin Gausman is the staff ace. He is ninth in the Majors among all starters in ERA, has the second-most strikeouts and is the team-leader in WAR.
José Berríos has enjoyed a renaissance this season, and is looking more like the version who was selected to two All-Star Games. In fact he's actually projected to record the lowest ERA of his eight years in the Majors (currently standing at 3.31) and is second on the team in WAR.
Remaining on the narrative of enjoying a renaissance, the same applies to Yusei Kikuchi, who no longer is so unpredictable on the mound. He's already set a single-season best with nine wins and is on course for the same in ERA (3.67) -- he's never before finished below 4.0 -- and WHIP (1.275).
Finally we have Chris Bassitt, who admittedly isn't having his best season, but isn't exactly pitching poorly either overall. Ultimately, if he's your third (or fourth) starter in the rotation, you're in a good position.
Overall, there's plenty to like about this rotation. And if Manoah can get back to even two-thirds of his dominance from last season, the Blue Jays will truly be set.