"Craig Tatum thanked Reds manager Dusty Baker for all the playing time he got at spring training.

"He didn't have to do that," Tatum said.

But Baker's motive was not entirely altruistic.

"In that catching position, there was a good chance we were going to need him," Baker said.

That time came Monday when Ramon Hernandez was placed on the disabled list with inflammation in his left knee.

Tatum, 26, was called up from Louisville to take Hernandez's roster spot. Tatum was the club's third-round pick in the 2004 draft. He was rated the organization's best defensive catcher last year.

"I liked him a lot in spring," Baker said. "I was surprised to see his average wasn't higher at Louisville with the way he hits the ball to right and right-center. That's usually a sign a guy's staying on the ball."

Tatum was hitting .239 with three home runs and 21 RBI for the Bats.

"There's going to be a learning curve to learn the hitters in this league," Baker said. "He knows most of the young pitchers."

Tatum has caught a lot of the pitchers on the Reds' staff - Homer Bailey, Daniel Ray Herrera, Carlos Fisher and Jared Burton - at Louisville.

Ryan Hanigan will get the bulk of the playing time in Hernandez's absence.

The spring training experience will help as well."