Since the addition of expanded replay reviews in 2014, Major League Baseball has faced some controversy with many pop-up slides being overturned. With that in mind, one veteran umpire sees an avenue for the rule to be improved.

"There are some things that happen that you don't have the ability to see with the human eye. That's difficult," 23-year veteran umpire Ted Barrett told Jesse Rogers of ESPN regarding the brief moments that players may come off the bag during a pop-up slide.

"You know, the National Football League has talked about changing the definition of a catch. We may have to change the definition of a tag. Umpires are used to using sound. When someone pops up off the bag for a split second, that's a whole other thing. Those are hard."

The veteran umpire, who's served in that role since 1994 and as a crew chief since 2013, also weighed in on MLB's new pace-of-play rules intended to limit mound visits, saying the league plans to put a running tally of visits on the scoreboard. As for policing it, that's still somewhat unclear.

"We're still working on it," Barrett said. "The iffy ones are when the infielder goes in. We're still working on some defining points, like if you go on the (mound) dirt or something like that. There has to be some guidelines for everyone ... By Opening Day, there will be no gray area."

Barrett added that getting batters into the box will be a priority this season.

"To start the inning, we want the hitter in the box as the catcher throws down to second," he said.