Walks. As in, free bases. Four balls. Giving the opponent 90 feet without having to make him work for it. And it drives the skipper crazy.
"It doesn't make any sense," Cooper said. "If you throw it over [the plate] and the guy hits a homer, that's not a rally. If you've got guys constantly on base and walking, it's terrible. I think it's just terrible."
From that perspective, it's been a long, and somewhat terrible, spring for the skipper. Entering Sunday's game against the Mets, the Astros had issued 58 walks, the second-highest total in the National League. The only team with more walks is the Giants, whose total of 68 was somewhat padded by Noah Lowry's nine in one outing, shortly before he had left arm surgery.
For the Astros, injuries are not the issue, command is.
"If you're working on changeups, I'd understand that," Cooper said. "But I don't even see that. I see us missing with fastballs, which is a concern. If you're missing throwing your breaking balls or changeup, OK. But these guys are missing with their fastball. No command."
With his hands spread about two feet apart, Cooper demonstrated how far off the plate pitchers were missing.
"Every time I look, it's not like we're 0-2, 0-1," Cooper said. "We're 3-1 every time. That shouldn't be. If you're going to get hit, get it over quick. Throw it over there. Your pace is good. That's what I like, even if you get beat."
Some of the control issues can be attributed to youth and inexperience, considering the number of pitchers who are in big league Spring Training for the first time. But some of the veterans are driving up the walk totals as well, which isn't sitting well with the manager.
"If we were running out all first-year [40-man] roster players and that was happening, well then, you've got to be patient," Cooper said. "But these are veteran people, Major League guys. We're not talking about kids.
"We've had one, maybe two games where [pitching coach] Dewey [Robinson] hasn't had to go to the mound and talk to somebody. He's wearing out a trail going out there. And these are guys that are, in many cases, experienced guys. And that is frustrating."
Cassel's outing: Rotation hopeful Jack Cassel had a walk-free outing on Sunday against the Mets, allowing two runs (one earned) over three innings.
Over seven innings this spring, Cassel has issued just one free pass.
"For me, that's always been my game, to pound the strike zone," Cassel said. "Work down in the zone with all my pitches and let the defense work behind me. For a guy like myself that doesn't necessarily have overpowering stuff, when I give the guys a free pass, I end up finding myself in trouble."
Cuts coming: The Astros could make their first round of cuts as early as Monday, and while Cooper isn't looking forward to calling players into his office to have "the talk," in terms of pitching, it's absolutely necessary to whittle down the roster soon.
Starting pitchers are building up innings to where they're up to three or four per outing, and with 10 pitchers in the running for starting jobs, there aren't enough innings for everyone. That will necessitate some of the candidates on the bubble to go to Triple-A Round Rock, where they can get on a regular routine.
"If you have two [starters] per day, that's going to get you, in most cases, six or maybe seven innings," Cooper said. "It's where you're not getting enough guys in there. You have a couple relievers, a couple starters and the rest are sitting there watching. We have to try to decide which guys we're going to do something with and do it."
Missed time: Felipe Paulino stood at his locker and blamed himself after his mediocre performance against the Nationals on Saturday, but the right-handed prospect may have had more reasons than just lack of command for his subpar outing.
Paulino recently had an infection in his right foot, which had to be cut out. That forced the righty to miss some time on the mound in between starts, which may have affected him on Saturday.
"He didn't get the mound time," Robinson said. "Practice time is really important, especially this time of the spring."
Up next: The Astros play at home in Kissimmee on Monday afternoon at 12:05 CT, with a matchup of terrific pitchers -- Roy Oswalt against Roy Halladay and the Blue Jays.
Alyson Footer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.