That gap between the two rosters is the whole story of this series opener. Los Angeles has the depth to fill a spot start with a serviceable arm and barely blink; St. Louis is running its bench and its rotation on fumes trying to find out who's part of next year's answer.
Neither team is exactly rolling. The Cardinals have dropped 2 straight and are 2-3 across their last five, having taken just 1 of the first 3 from Pittsburgh in a series still working itself out. The Dodgers are technically 2-3 in that same window too, but they enter off a win, having taken 2 of the first 3 from Detroit before that. The difference is context — LA's stumbles are the kind a division leader can shrug off; St. Louis's are symptoms of a season that was lost a while ago.
McGreevy's last time out was a mess — 7 earned runs allowed against Baltimore in a start where he couldn't finish the fifth inning — and his walk and hit totals have crept up all summer. Lauer, by contrast, has actually pitched well since arriving in LA earlier this year, even if his season-long numbers look middling on paper; getting bumped back into the rotation is less a sign of trouble than the Dodgers protecting their six-man setup instead of calling someone up before September 1 arrived.