The A's vocalized how confident they are in their rotation prior to Wednesday's spring training report date.

That confidence stretches beyond the coaching staff and all the way to former A's pitcher Dave Stewart.

Stewart, now an analyst with NBC Sports California, sees bright spots in the young arms for the 2020 season.

"I do like the rotation that we could possibly be seeing in the upcoming year," Stewart told NBC Sports California back in December. "It'll be pretty dominant if the kids that pitch in the rotation that we think are."

Stew mentioned the combination of lefty power arms in A.J. Puk, Sean Manaea, and Jesús Luzardo. Adding right-handers Mike Fiers and Frankie Montas, has the A's pitching squad looking very promising.

"In my opinion, that now brings your rotation that's respectable, and will probably be, if you really look at the rotation, assuming that they're going to be successful," Stewart added.

Stewart admitted, despite the exciting times ahead with this group, "today's baseball" isn't something he's used to -- especially with piggy-back starters. He's asked often if any of the pitchers on the staff remind him of his younger self.

"Today's brand of baseball is way different from my brand of baseball, so there are no reminders of me," he laughed.

Stewart, who recently had his No. 34 jersey retired by the A's, is often around the team to offer advice on anything they might need.

"We have to be careful of innings pitched because most of the kids that are coming to the big leagues, at this point in time, they have not logged major league innings," Stewart said. "They haven't pitched 100, 175 innings in a season."

You always have to look to the future organizationally. And how you can best keep these kids healthy so that a year from now, two years from now, three years from now, they've adapted and now they've become mainstays."

The 6-foot-7 Puk underwent Tommy John surgery in April 2018, and by the looks of it from his throwing sessions on Wednesday, he fortunately looks healthy and strong. He came out of the bullpen last season during his 10 games in the bigs, but is slated to be a starter this season.

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Despite a few setbacks, Luzardo made his highly anticipated debut in 2019 and was sensational, finishing his short campaign with a 1.50 ERA and 0.67 WHIP over 12 innings. The A's also will get a full season of Frankie Montas after missing a chunk of time last year due to a PED-related suspension.

"It'll be a rotation that has depth from one through five, capabilities of winning on any given day, because all those kids, they're, in my opinion, future superstars as starting pitchers," Stewart said.