KANSAS CITY -- Mark Teahen of the Royals has mixed feelings about the onset of instant replay's arrival in the Majors for home run calls starting on Thursday.

On one hand, he remembers losing a home run last season at Detroit.

"It was a first-pitch slider from Nate Robertson and I hit it to right-center in Detroit. I think the fence has a yellow line and there's a little metal fence above the padded fence. And I think it hit that and came back and I ended up getting a triple on it," Teahen recalled. "It was a home run, I'm pretty sure."

Conceivably, if instant replay had been in effect, he would have had a homer. On the other hand ...

"I'm torn on it," Teahen said. "The human element is what makes baseball the game it is and I definitely don't ever want the game to go to instant replay for close plays or anything like that or end up having the strike zone called by computer.

"I think the human element is important for baseball so as long as -- and I know this was an important part of the players' union agreeing to it -- we keep it limited only to home runs, so we're not opening a Pandora's Box."

Royals manager Trey Hillman has favored the instant replay on home run calls since it was first proposed. He believes it will make the umpires' job easier.

"I agree with a lot of the reports that say, with some of the configurations of the ballparks, it takes a little pressure off the umpires. These guys got a lot of pressure on themselves with what they do," he said.