The Nationals' aim to repeat as National League East champions seemingly became more difficult yesterday, when the Atlanta Braves traded for Justin Upton in a seven-player deal with the Arizona Diamondbacks. General Manager Mike Rizzo drafted Upton with the first overall pick in 2005 as the Diamondbacks' scouting director, and he believes Upton is a great addition for the Braves, who won 94 games last year. But he considered the key player the Braves gave up – utility man Martin Prado – to be just as significant as what they received. "I haven't had a chance to digest the whole trade yet," Rizzo said Thursday evening before he received his Executive of the Year award at the Boston baseball writers dinner. "But Prado is a terrific, terrific baseball player. He's a different type of contributor than Upton would be. Upton is a terrific player and a guy I'm very familiar with and I love. He's going to be a good player for them. "He's a great player. They had a good team before they got him. They've got a good team now. It's going to be a different team than we've seen in the past because Prado is really a thorn in our side. He was always a tough out for us and really one of their most valuable players against us throughout his career."