It happens every year. You're cruising along without a care in the world when, suddenly, your best pitcher ... just stops pitching.
OK, so full shutdowns are no longer as common a method of innings management as skipped turns and early hooks, but teams that fall out the race are still known to hit the brakes from time to time. The bottom line is that you want to be prepared. The start of the second half is a good time to take stock of where younger pitchers are with their innings and potentially make some moves before the curtailing begins en masse.
Like, would you dare trade Shane McClanahan, who's been arguably the best pitcher in Fantasy to this point but is already nearing a career-high in innings? What about Alek Manoah? In both cases, you'd probably want another surefire ace in return (maybe more in McClanahan's case) to avoid selling low, but now is the time to consider such a move, before it's obvious to everyone what's happening.
Generally, an increase of 40-60 innings from one year to the next is acceptable, though it's not a hard-and-fast rule. Presuming a five-man rotation, most pitchers have 13 turns left. At five innings a start, that's 65 innings. Using that criteria, I've identified 18 pitchers who might not hold up. It doesn't mean they'll all be shut down, of course. For each, I offer my concern level as well as a description for how things could possibly play out. It's up to you to make a judgment call from there.
To preempt some of the what-abouts, I also considered Carlos Rodon, Kyle Wright, Triston McKenzie and Aaron Ashby for this exercise but decided they weren't at major risk of a shutdown or even a slowdown.
Note: Innings counts include minor-league and postseason totals. This year's are up to date through Monday, July 25.