Caleb Smith's outing was decided by mere inches on Tuesday.

With a scoreless game and a runner on third for Cardinals third baseman Nolan Arenado in the fifth inning, Smith’s 2-2 four-seamer left Arenado's bat at 106.1 mph and sailed down the left-field line. A fair ball would have barely enough distance to make it over the wall, a foul ball would give Smith another chance to escape the inning unscathed.

That chance wouldn’t come, though. Arenado’s hit stayed in fair territory long enough to bounce off the foul pole, and even though it was Smith’s only blemish in his five innings of work, it made the difference as the D-backs dropped the second game of the series, 3-2, at Busch Stadium.

“I thought he did a really nice job,” Arizona manager Torey Lovullo said. “We were going to stretch him out a little bit. I had a certain number in mind if he got through, we were trying to get him through six [innings]. His stuff was pretty good today. I think he made a mistake or two. A ball gets hooked around the left-field foul pole for the only two runs that he gives up -- I'll take that.”

“I could've done without the two-run homer,” Smith said. “I think that would've been ideal, but I mean, he's a good hitter. He gets paid a lot of money to do that.”

Smith nearly came out of the game without the chance to face Arenado in the bottom of the fifth.

In the top of the inning, the D-backs had runners on first and third with two outs against Cardinals starter Carlos Martínez with Smith due to bat. Lovullo either had to leave Smith in to hit against Martínez with the go-ahead run 90 feet away, or he had to pull Smith after four innings of scoreless ball -- a dilemma similar to one Lovullo faced in the sixth inning of Monday’s game.

The choice to let Smith hit ultimately worked in St. Louis’ favor, however. Smith bounced out to Arenado to end the threat, and with two outs in the bottom frame, Smith instead gave up the go-ahead runs on Arenado two-run shot.

“He's been one of our best starters, and I didn't want to take him off the field,” Lovullo said about the decision. “The game was tied, he hadn't given up any runs and we were going to try and get two more innings out of him. That was my mindset.”

But despite taking his fourth loss of the year, Smith was impressive. He tied a season-high with eight strikeouts, started 15 of the 23 batters he faced with strikes and allowed only four hits.

With that hit total, Smith entered some rare company among D-backs pitchers. Tuesday marked his seventh start of the season, and he has allowed fewer than six hits in each. That put him in a three-way tie for the most consecutive starts with five or fewer hits allowed to start a season in Arizona history with Randy Johnson (‘00) and Yusmeiro Petit (‘08).

An early rising pitch count (he threw 64 pitches by the end of the third) prevented him from going back out for the sixth, but Smith’s outing was necessary to keep Arizona within striking distance on Tuesday.

“He really was commanding his glove-side fastball really well and had some really good breaking balls,” catcher Stephen Vogt said. “Unfortunately, he left the one pitch to Arenado out over the middle, but I thought overall, he made some really good pitches.”

On a macro-level, Smith provides an interesting option for teams looking for a pitcher who can start or come out of the bullpen (he has a 3.41 ERA as a starter and a 2.70 ERA as a reliever). He’s allowed no more than two runs and four hits in five of his last six starts since returning to the rotation, continuing the success he experienced as a reliever, when he gave up more than a run in just three of 18 appearances out of the bullpen.

He also has a 1.27 WHIP and a .206 opponents’ average on the year, marks that rank third and second, respectively, on the team among pitchers with at least 10 appearances.

Only a month remains before the July 30 Trade Deadline, and with Tuesday adding to his recent string of solid performances, Smith continued to display his potential as an Arizona trade chip.