HOUSTON -- On the first day instant replay will be available in Minute Maid Park, Astros manager Cecil Cooper said the technology is long overdue.

Cooper has been a proponent of the use of instant replay in home run boundary-call situations since the conversation started earlier this season, saying the umpires sometimes need assistance.

"A lot of times, umpires just can't turn around and get out there quick enough," he said. Cooper said he often has a hard time when a ball is hit to left-center field. The light from outside combined with the white Waste Management sign makes seeing the ball tricky.

In fact, Minute Maid Park is one of the reasons instant replay was instituted. With its odd boundaries, a lot of hits are ambiguous there.

"It's hard in some of those little quirky places," Cooper said. "Sometimes a homer doesn't even leave the ballpark."

About five home runs in Houston's park have been questionable this season.

The New York Times reported that about 18 home runs this season from around the league would have been subject to review had instant replay been instituted. That number, estimated by Jimmie Lee Solomon, MLB's executive vice president of baseball operations, amounts to about a home run every week in the first four months of the season.

Still, general manager Ed Wade voted against instant replay.

"It could become a slippery slope issue where we start out with fair or foul, and before you know it we're reviewing a lot of things," Wade said. "Weighing a few calls here or there that could be critical against the backdrop of playing really long games when there seems to be a parallel effort to try to move the pace of the game along -- I just think this is an issue that could create other issues along the way. Hopefully the people who voted in favor will end up being correct."

Wade said now that replay is instituted, the Astros will fully support the system. But Cooper hopes all the Astros' home runs will be definite.

"I hope it works because we need it," he said. "But I hope I don't have to use it tonight."