The Nationals have promoted right-handed slugger Tyler Moore from Class AAA and will place veteran bench player Mark DeRosa on the disabled list. Moore, 25, began playing left field recently but has played only first base throughout his career. Most importantly, he could provide a power threat off the bench.

Moore has consistently become one of the Nationals best slugging prospects since they drafted him in the 16th round in 2008 out of Mississippi. He has hit 69 home runs since the start of 2010, including seven this year, the most in the entire organization. In 22 games at Syracuse, Moore slugged .597.

Moore’s ascent began in the middle of 2010, when he was hitting .195 for Class A Potomac. He met with hitting coach Matt Nokes, who told him to stop thinking so much at the plate, to relax and swing with aggression. The meeting touched off an incredible six-week stretch in which Moore won the Carolina League player of the week award four times and punched up 1.406 OPS.

Moore continued hitting at Class AA Harrisburg last season, drilling 31 homers for the second straight season and 35 doubles. The Nationals added Moore to their 40-man roster this winter, and he spent the first portion of spring in major league camp.

It is not clear at this point what DeRosa’s injury is.