A spot has opened for odds favorite Rachel Alexandra to run in the 134th running of the Preakness Stakes, ironically thanks to the owner of Triple Crown contender Mine That Bird.

Mine That Bird owner Mark Allen said Monday he wouldn’t enter colt Indy Express into the second jewel of the Triple Crown. That clears the way for the Kentucky Oaks winner to enter the field of 14 for Saturday’s race at Pimlico.

Allen had considered entering Indy Express — winless in nine career starts — over the weekend to take a spot from Rachel Alexandra, but he reconsidered after talking to Mine That Bird trainer Bennie Woolley Jr. and co-owner Leonard Blach.

The race is limited to 14 starters, with preference given to those already pre-nominated to the Triple Crown.

Good for Allen. He would have been vilified had he entered a winless Indy Express just so that Rachel Alexandra (Mine That Bird’s chief competition) couldn’t run in the Preakness.

Rachel Alexandra has been flawless so far in 2009, winning seven of her last nine races. She would add a little excitement to the Preakness, especially after Mine That Bird won the Kentucky Derby two weeks ago despite being a 50/1 long shot.

Despite reports that stated he could miss the second leg of the Triple Crown, 2009 Kentucky Derby winner Mine That Bird will run in the 134th running of the Preakness Stakes on May 16.

Trainer Chip Woolley had wavered because the mile-and-three-sixteenths Preakness at Pimlico racecourse on May 16 is the shortest of the Triple Crown races and Mine That Bird performs better at longer distances.

“You cannot have a Triple Crown winner without having the Derby winner in the Preakness,” Woolley told the Pimlico racecourse website (www.pimlico.com).

“That played into our decision but the horse looks super. I have never been to Baltimore, but it looks like I won’t be able to say that in a few days.”

Kentucky-bred Mine that Bird, a 50-1 longshot ridden by Calvin Borel, won the Derby Saturday by 6 3/4 lengths, one of the biggest upsets in America’s most celebrated race.

The sport of horse racing would have taken a huge hit had Woolley pulled Mine That Bird from the Preakness Stakes – especially considering how much of a long shot winner Mine That Bird was at the Kentucky Derby.

The Triple Crown is such a rare feat in sports and just like Big Brown last year, it’s fun to get behind a horse that’s in the running for it. Hopefully Woolley doesn’t pull an about-face and pull Mine That Bird leading up to the Preakness.