Stewart was asked Saturday if he might be in the market for starting pitching prior to the July 31 non-waiver Trade Deadline given the uneven performance of the rotation so far this year.
"Not if we had to trade for it, [and] we'd have to trade for it," Stewart said. "We want to be competitive and we want to win baseball games, but we're not going to take a step backwards by trading guys that are going to be helpful to us going forward."
The D-backs are looking at the return of injured pitchers Patrick Corbin and Bronson Arroyo as a way to bolster the bullpen. Corbin, who will next start for Double-A Mobile as part of his rehab assignment, could be back in a few weeks, while Arroyo is not due back until later this year.
The D-backs' prized young starting pitchers -- Aaron Blair and Braden Shipley -- are currently in Mobile, but could be options later this year.
"My thought is I wouldn't want to call them right now," Stewart said. "But to give you an example, Blair is throwing the ball good. If he's throwing the ball good in another month, then we'd probably have to consider him if we need starting pitching. It really just depends on what they're doing, how well their doing at the time we have a need."
Stewart made acquiring young pitching a priority last winter, and he said he will continue that this offseason.
Plus, the club took a number of college pitchers in the recent Draft that could make an impact in the next couple of years.
"Keep building, building from within," Stewart said. "If we've got an opportunity in the upcoming winter to pick up some more young pitching, we'll do that. And then relying on the guys that we have here."
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.