MLB rules don’t specify that a dog can’t play baseball. The Nationals won’t be testing that, even as they called up Bruce the Bat Dog on Tuesday afternoon.

The trained pup will make his major league debut on Saturday before Washington’s home tilt against the Miami Marlins.  Bruce the Bat Dog will only be on the field for a pregame ceremonial bat retrieval. 

Bruce spent three games honing his bat retrieval skills with the Triple-A Rochester Red Wings. He posted a “1.000 retrieving average,” the Nationals said in a release.

Bruce will only be on the field for a pregame ceremonial bat retrieval before returning to Rochester, a spokesperson told the Associated Press.

The one-year-old dog will make one more minor-league appearance on Friday before joining the Nationals for the middle match-up of a three-game series against the Marlins.

“Our fans and front office are always excited to see our players get promoted to the Nationals, but Bruce’s promotion is a historic call-up to the big leagues that he richly deserves,” Rochester Red Wings General Manager Dan Mason said. “Nobody makes people smile more than Bruce.”

Bruce will fittingly join the Nationals for a “Pups in the Park” game on Saturday. Fans can purchase special tickets to receive a pet bandana, with proceeds supporting the Humane Rescue Alliance. Adoptable dogs from Wolf Trap Animal Rescue will be featured at a “puppy lounge” in the ballpark.

Topps is honoring Bruce’s big league debut with his own trading card. The limited-run card will be available online for 24 hours.

“He has proven himself to be ready for the show in a very short time and has earned the phenom status that has been bestowed upon him,” Mason said of Bruce. “He’ll put on a doggone great show for Nats fans on June 14.”

• Liam Griffin can be reached at lgriffin@washingtontimes.com.