By Josh Cook

Get ready for a glimpse of greatness Louisville.

But don't blink, because you might miss Aroldis Chapman and his blazing fastball.

The 22-year-old, who was considered by many scouts the best left-handed pitching prospect in the world when he defected from Cuba in July of 2009, signed a six-year, $30.25 million contract with the Cincinnati Reds in January. He was expected to compete for the job of Cincinnati's fifth starter in the Reds' pitching rotation during spring training, but a back injury shelved him for a short time and he lost his chance. He was optioned to the Louisville Bats, the Reds' Triple-A affiliate Friday.

"We felt, competition-wise, that's where he should be," Reds general manager Walt Jocketty told MLB.com on Friday. "We just felt competition and environment, and so forth, were better. Plus, they've got some long bus rides in (Double-A) Carolina."

The 6-foot-4, 185-pound Chapman, whose fastball reportedly registered between 97 and 100 miles per hour in spring training, spent the spring learning English as well as honing his skills. His expected emergence is one reason why the Reds have been labeled a team "to watch" this season.

In five spring training appearances Chapman went 1-0 and struck out 15 in 10.2 innings, while walking seven and allowing two earned runs to post a 1.69 ERA. His stay in Louisville will likely only be a brief one, though.

The Bats open their season Thursday with a four-game series in Toledo. Then they travel to Columbus for a two-game series before returning to town for their home-opener against Indianapolis at 7:05 p.m. April 14.