HOUSTON -- As Astros players were stretching for batting practice, a small group of Astros and Major League Baseball officials gathered in left-center field, next to a crane and a big can of yellow paint.

In response to a somewhat controversial call made during Monday's series opener between the Cubs and Astros, officials reworked one of the yellow lines that indicates a home run, located just to the right of the "bmcsoftware" sign above the visitors' bullpen in left-center.

Bob Watson, MLB vice president rules and on-field operations, called it a more "umpire-friendly" line, which will better differentiate between a home run and a ball in play.

A yellow wood board that served as a home run indicator was removed, and in its place is a simple yellow painted line, drawn on the inside part of the wall.

The confusion emerged during Monday's game, when Geovany Soto smacked a hit off that area in left-center field and made it all the way around the bases for an inside-the-park home run. The umpires couldn't tell where the ball hit the wall, so they ruled it in play.

Any ball hit on the yellow line at Minute Maid Park is ruled in play, while anything above is a home run. The ball had a yellow mark on it, which indicates the umpires made the right call.

Watson is hoping the newly painted area will make it easier for the umpires to make a quick ruling.

"There's no need for that type of confusion in a big league ballpark," Watson said. "It's umpire-friendly. He can make the call on the move."