The Blue Jays headed into last season unsure how their rotation would stack up in the tough American League East.

Pretty well, it turned out, as Toronto rode its strong starting pitching all the way to the American League Championship Series.

With most of that core returning for 2017, right-hander Marcus Stroman believes the Blue Jays will enter this season with the most fearsome starting five in the majors.

"I think we have the best rotation in baseball, hands down. I'll argue that day-in, day-out," Stroman said recently at the Blue Jays spring training facility in Dunedin, Fla.

"We weren't valued at all coming into spring training (last year) ... but we knew what we were capable of. One through five, we were extremely strong, each and every guy I consider pretty much an ace and can get us a win every day. That's the mentality we have."

After a successful 2015 season, Blue Jays president and CEO Mark Shapiro opted not to go after big-name free-agent pitchers, signing left-hander J.A. Happ and re-signing righty Marco Estrada instead. Both moves paid off in 2016.

Happ had a career year, earning 20 wins for the first time and Estrada, though hampered with a back injury for much of the season, was named to his first all-star game while helping lead Toronto to a second straight ALCS appearance.

Stroman, the MVP of this year's World Baseball Classic, is poised for a strong season while sturdy veteran Francisco Liriano is back after coming over in an August trade with Pittsburgh.

Aaron Sanchez, who effectively shrugged off any talk of an innings limit to finish 15-2 with 3.00 earned-run average in 2016, rounds out the starting five.

"(The rotation) was one of the areas that a lot of people doubted us last year and we kind of took that with some fire underneath us," Sanchez said. "We tried to prove to people that we were for real about this and I think it's something we'll try to continue.

"Everybody worked extremely hard and hopefully we can stay healthy like last year and proceed to do the same if not better."

The Blue Jays enjoyed remarkable health among their rotation last season, only using seven starters in total. R.A. Dickey pitched 169 2/3 innings and Drew Hutchison filled in as a spot starter twice.

As a group, Toronto's rotation led the American League in ERA (3.64), innings pitched (995 1/3) and opponents batting average (.236).

But manager John Gibbons knows that success won't be a given in 2017 as Toronto hopes to advance to the World Series for the first time since 1993.

"It's a new year, you have to go out there and do it again," Gibbons said. "I think (the starters) were all better than we thought they were going to be. Honestly, yeah, they rank up there (with the top rotations in MLB).

"We were fortunate, we stayed healthy and we need to do that again. But I'd put them up there with anybody."

Estrada, named the opening day starter last week, says the strength of Toronto's rotation is in its lack of a true ace.

"I don't think we have to rely on one guy," Estrada said. "I mean, we all want to be good and we do have to be good but it's not all the pressure on one person and it makes things a lot easier.

"The whole ace term, whatever. We have five guys that can compete. We're really good. Any one of us can start the first day and we'll feel good about it."

Toronto feels good about its offence, too.

The return of free-agent slugger Jose Bautista will provide a familiar boost alongside 2015 AL MVP Josh Donaldson and all-star shortstop Troy Tulowitzki.

Toronto will miss Edwin Encarnacion's power, but former Kansas City switch hitter Kendrys Morales will fill in at the designated hitter spot. Coming over from the AL Central, a largely pitcher-friendly division, Morales could enjoy a swell of production in the hitter-friendly AL East stadiums.

Donaldson says Toronto has the potential to be a well-rounded team this year.

"Last year I felt we underachieved as a whole offensively. Hopefully this year (the offence) comes back to where it was in 2015," Donaldson said. "What you saw last year is our pitchers really took the bull by the horns and did a great job and it was phenomenal ... They went out and proved a lot of people wrong and I think they have the capability to do it again.

"Hopefully we're a more balanced team because both sides are better."

Melissa Couto, The Canadian Press