TAMPA – What you read starting with the second paragraph comes with a warning: It’s only batting practice in February.

Yet, it was impossible to not be impressed by how well Randy Johnson threw BP yesterday at Legends Field.

His fastball produced rivers of white and his slider was filthy.

And if you have any doubt, or wouldn’t trust hearing it from Johnson, consider Jason Giambi’s take:

“His slider was as good as I have seen,” said Giambi, who had his shirt grazed by a fastball.

“He hid it pretty good and it was down. He looked very good to me.”

Johnson also faced Derek Jeter, Johnny Damon and Wil Nieves. He also threw to Ben Davis, who was impressed.

“He got a lot of reaction on his slider,” Davis said.

In his second BP session, Johnson threw 67 pitches and was generally pleased.

“I have a better feel for it right now,” Johnson said of the slider.

In addition to his sharp slider, Johnson was pleased with is mechanics.

“It’s a good feeling not to think about it,” said Johnson, Joe Torre’s unannounced Opening Day starter. “Everything seems to be where it needs to be.”

Johnson will likely throw BP Wednesday and make his exhibition season debut Saturday against the Reds at Legends Field.