Right now, even with a rotation that ranks second to San Diego's in the National League with a 3.03 ERA, the warning signs are flashing.
While the Cardinals figure to get right-hander Brad Penny back when he's eligible to return from the disabled list June 7, there is no timetable -- yet -- for Lohse's return.
And though rookie Jaime Garcia (1.14 ERA, 11 consecutive scoreless innings) has been sensational, he underwent Tommy John ligament transfer surgery in September, 2008, and only pitched a total of 37 2/3 innings combined at three minor-league levels in 2009.
Which all likely will put St. Louis in the market for more starting pitching at some point this season. Seattle's Cliff Lee, Houston's Roy Oswalt, Cleveland's Jake Westbrook and possibly even Oakland's Ben Sheets are all among the names expected to become available between now and the July 31 trade deadline, though La Russa -- whose club acquired John Smoltz last year -- isn't allowing his imagination to run wild at this point.
"I think it will come from within [the organization]," La Russa said of any eventual pitching reinforcements. "Mo [general manager John Mozeliak], can answer that better, and maybe differently. But I haven't heard anything different than from within."
It isn't that the Cardinals are anywhere close to trouble now, even with Lohse headed into unknown territory to undergo surgery for an injury to which there apparently is no precedent in major-league baseball.
"I think we'll get Penny back [when his DL stint is up]," manager Tony La Russa said Thursday. "That means we'll have four solid guys. There's a question mark on Lohse. But everybody has problems."
Until the Cardinals get Penny back, they're down two-fifths of their rotation. As La Russa said, for one thing, that gives an opportunity to rookie P.J. Walters, who made just his second career start on Thursday in San Diego.
The kid stepped up to the challenge, throwing five shutout innings. He allowed four hits, struck out four and walked two.
Saturday in Chicago's Wrigley Field, Adam Ottavino, the Cardinals' first-round pick in 2006, is expected to make his first major-league start. Another opportunity.
Garcia, 23, certainly has made the most of his. He's worked six or more innings and allowed two or fewer earned runs in each of his first seven starts, and the last rookie to do that was named Fernando Valenzuela, back in 1981.
The issue is, if Garcia continues pitching this well, it's hard to see how there won't be a breaking point when he reaches a certain number of innings. What are the Cardinals going to do, allow a prized kid less than two years off of Tommy John surgery to, say, quadruple his innings-pitched load from last year? He's at 55 1/3 innings pitched so far in 2010.
"You can't speculate," La Russa said. "All you can do is watch closely. He never really forced it ... you really have to wait and see how the season develops. We're going to be really careful with him."
Lohse was diagnosed this week with exertional compartment syndrome, an uncommon, exercise-induced neuromuscular condition that causes pain and swelling in the legs or arms. As St. Louis Post-Dispatch beat writer Joe Strauss reported, it is most common in marathon runners and motocross drivers. Athletes in those sports generally have resumed activity within six-to-eight weeks, though, as a pitcher, Lohse is expected to take a longer.
La Russa said Thursday he figures Lohse will return "this year. Other than that, we just have to wait."