One byproduct of this team playing so many close games this season has been a heavy reliance on Rosenthal, who ranks seventh in the league with 59 appearances and first with 42 save opportunities. He has converted 37 of them, a rate comparable to Francisco Rodriguez and Craig Kimbrel. Though Rosenthal's outings are routinely stressful, the conversion rate continues to give him the stranglehold on the closer job.
If the Cardinals are going to continue to tangle in so many close affairs, Rosenthal's ability to have a strong finish -- or Matheny's willingness to make a closer change, if that becomes necessary -- will be pivotal. The Cards have been more liberal with rest for Rosenthal recently in hopes of not having to make a September closer swap for the second straight year.
The Cardinals have actually gained ground on the Brewers since Yadier Molina went down with a thumb injury the second week of July, though that is not indicative of how much he's been missed. The pitching staff is better with Molina behind the plate -- this year more than a run better, with Molina's 3.26 pitchers' ERA. He'll have some new pitchers to learn once he returns, but Molina's learning curve should be brief.
The Cards have also found it harder to stop an opponent's running game without Molina. He has thrown out 49 percent of attempted basestealers in 2014, and his three replacements (Tony Cruz, A.J. Pierzynski and, briefly, George Kottaras) have combined for 18 percent.
Molina not only makes his pitchers better, but he makes the lineup deeper. While his production has dropped from its 2012-13 levels, Molina was still among the Cardinals' harder outs. He had reached safely in 64 of 81 games before tearing a ligament in his thumb and has the longest hitting streak (15 games) of anyone with the team this season. Molina's slash line of .287/.341/.409 was among the league's best at the position.
A series of MRIs has shown progressive improvement in Wacha's right shoulder, and that provided the clearance for the right-hander to resume throwing. He's pitching off a mound now, hopeful of getting out on a rehab assignment before the end of the month and eyeing a September return.
Everyone remembers what Wacha meant to the Cards' postseason run a year ago, when he wrapped up the regular season by coming one out away from a no-hitter and then rolling to a 4-1 record with a 2.64 ERA in five postseason starts. If he can return healthy and to pre-injury form in September, St. Louis will boast a rotation with four front-line starters. The rotation averaged 6 1/3 innings per start before Wacha's injury and 5 2/3 innings per start since.
Using Wacha in the bullpen remains the backup plan for the Cardinals, as their preference remains bringing the right-hander back to start. He had a 2.79 ERA in 15 starts (12 quality ones) before the stress reaction shut him down.
Wainwright's place on this list highlights his importance as an ace, something of which St. Louis will need him to be down the stretch. There is little to nitpick of Wainwright's season thus far, which features 15 wins and 20 quality starts. He has not, however, been as dominant as of late, and that has made him vulnerable. The Cards have lost three of Wainwright's last six starts after losing only four times with him on the mound in the first half.
After making eight starts of at least eight innings through June, Wainwright has had none in July and August. He featured a 1.83 ERA and .201 opponents' batting average heading into the All-Star break. Since then, those figures are 4.50 and .275, respectively. Wainwright has described this last month as a "grind."
Wainwright has been good as of late, but not great. And with other unknowns regarding their rotation, the Cardinals need him to trend toward great.
It's also notable that the St. Louis recently tweaked Wainwright's schedule so that he will appear in both of the series the Cards will play against the Brewers and Pirates.
The team's July trade of Allen Craig eliminated a timeshare in right field and opened an opportunity for Taveras, the organization's top prospect entering the season, according to MLB.com, to get the everyday playing time that many hoped would accelerate his influence. To this point, it really hasn't.
Taveras isn't unique as a highly-touted prospect to struggle in his first exposure at the Major League level. But if the Cardinals are to get their offense clicking down the stretch, Taveras will have to be a part of it.
Production from that right-field position has been terrible for St. Louis this year. The club ranks last in the NL in runs scored (42), slugging percentage (.314) and OPS (.585). Only two NL clubs have fewer RBIs from their right fielders.
Taveras was a prolific hitter in the Minors (.320/.376/.516 slash line over 1,676 at-bats), so there is certainly the potential for him to emerge an impact bat at any time. The shorter that learning curve, the greater the benefit for the Cards, who have watched Taveras trudge to a .224/.263/.298 slash line over his first 50 games. His effort and work ethic have come into question a few times, though St. Louis is encouraged by the way Taveras has taken to instruction.