On Monday night in St. Louis, venerable Cardinals right-hander Adam Wainwright will take the mound against the Pirates. Wainwright, thanks to elbow inflammation, hasn't appeared on a big-league mound since May 13. Not so long ago, he turned 37, and he hasn't been both healthy and effective since 2014. 

Of course, it's September, and Wainwright is in his walk year. The Cardinals aren't thinking long here. They're thinking Wainwright can help them cling to that second wild-card spot in the NL or perhaps even climb higher in the ranks over the final fortnight-plus of regular season. Given the tight margins and given that the Cardinals' remaining schedule is a pretty tough one, you can assume this isn't a "ceremonial gesture" start by the St. Louis stalwart. He's getting the nod because the rotation is somewhat thin right now and because the decision-makers think Wainwright can give them a chance to win. 

In Wainwright's favor is how he fared in his minor-league rehab assignment. The competition is self-evidently lesser, but consider what Wainwright did in six rehab appearances spread across three levels:

Adam Wainwright
STL • SP • #50
Rehab assignment, 8/13-9/1
IP17
H12
R0
SO23
BB4
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So those are excellent results, to say the least. There's also this from his final appearance for Triple-A Memphis: 

Sure, sitting 89-90 doesn't sound impressive in 2018, but consider Wainwright's pre-injury velocity trends this season: 

brooksbaseball-chart-wainwright-velo.png
BrooksBaseball.net

You see the notable dip when he pitched while injured against the Padres on May 13. With his five-pitch repertoire, 89-90 is playable for Wainwright. Get much lower, and he's not a big-league pitcher. So getting the fastball and cutter up to 90 or so and keeping it there will be key for Wainwright against the Pirates on Monday, as will limiting walks, which uncharacteristically has been an issue at times this season. No, he's not likely to give them much length, but in the expanded-roster period the Cardinals right now are carrying a 12-man bullpen. They don't necessarily need Wainwright to pitch into the seventh or even sixth inning (though they'd certainly welcome it if he could). It's also a bit of a soft landing for Wainwright, in that the Pirates this season have been comfortably below average in terms of production against right-handed pitchers. As well, their most productive hitter in 2018 to date, Gregory Polanco, is out for the remainder of the season. 

As for the road ahead, much will hinge on how Wainwright fares against the Pirates. Under normal circumstances you don't want to react overmuch to an isolated start, but the Cardinals don't really have time to do anything but that. Assuming they use off days to skip Wainwright's turn, he'll have at most two starts left after this one. If there's no juggling, then they'd be especially vital starts -- against the Dodgers and then Brewers, most likely. If Wainwright inspires confidence against Pittsburgh, then perhaps he gets another turn. If not, then perhaps the Cardinals will hope his hard stuff plus curve will play up in a relief role, which is certainly a reasonable assumption. 

That Michael Wacha recently suffered a setback in his rehab in some ways clears the path for Wainwright to stay in the rotation, but he'll have to pitch his way there. With pitching, it's often said it's more about skill retention than age. We know Wainwright's age, and Monday night will give us at least a glimpse of whether recouped health will allow him to defy that age. The Cardinals, locked in a playoff struggle, need him to do just that.