Rockies rookie Senzatela faces test from Nats

DENVER -- The Colorado Rockies could use another strong start Thursday from rookie Antonio Senzatela as they seek to split a four-game series with the Washington Nationals.

Washington's rampaging offense in the past two games crushed Colorado starters German Marquez and Tyler Chatwood, who worked a combined nine innings and allowed 28 hits and 13 runs as the Nationals won 15-12 on Tuesday and 11-4 on Wednesday.

Senzatela starts against Nationals left-hander Gio Gonzalez starts in the series finale.

First baseman Ryan Zimmerman has been a big part of the offensive surge for the Nationals, whose 15-6 record is the best in the majors. Washington has won nine of its past 10 games and is 8-1 on a road trip that ends Thursday.

Zimmerman went 3-for-5 on Wednesday with a homer, his eighth of the season, and three RBIs. He has homered in three of his past four games and five of his past eight. Zimmerman is hitting .387 with seven doubles, eight homers, 21 RBIs and 16 runs. He has a .439 on-base percentage and an .800 slugging percentage.

"It's great to see Zim having success because he was used to success," Nationals manager Dusty Baker said. "He had success before I got here. It's a beautiful thing to see him doing well.

"He's hitting the ball on the line. He's not missing pitches. He's not going after bad pitches most of the time. And, man, it's just great to see. Everybody loves him. He invigorates a lot of life in the team."

Gonzalez (2-0, 1.35 ERA) has pitched at least six innings in each of his four starts and has allowed two homers in 26 2/3 innings. He won his last outing, giving up two hits and one run in 6 1/3 innings Saturday at New York in the Nationals' 3-1 victory over the Mets.

Gonzalez is 3-0 with a 3.86 ERA in four career starts against the Rockies and 1-0 with a 6.00 ERA in two starts at Coors Field.

Senzatela (3-0, 2.08) has won three straight starts and will make his fifth career start and his debut against the Nationals. The Rockies have won each of his four starts, including Saturday against San Francisco, when he pitched seven innings for the second straight game and gave up one run on four hits with no walks and three strikeouts.

The 22-year-old has allowed four walks while striking out 17 in 26 innings. He is 2-0 with a 1.93 ERA in two starts at Coors Field.

Senzatela had not pitched above the Double-A level before this season.

"Nothing really affects him or bothers him," said catcher Dustin Garneau, who likely will be behind the plate Thursday. "He understands who he is and what he can do. That correlates to the stuff he has. ... His fastball's above average, and he knows it. His off-speed's coming along, but it's getting better to where he can use it and keep guys honest to where they don't sit on his fastball."

Senzatela's repertoire includes a fastball that will reach the upper 90 mph range, a slider that is improving and a changeup that he throws a few times a game but has gotten much better.

Referring to Senzatela's fastball, Garneau said: "It's hard. It spins through the zone. It naturally cuts sometimes at 97 (mph). It's a really, really good fastball to both sides of the plate. He can throw inside when he needs to, either for strikes or to keep guys honest."

Garneau said of Senzatela's slider, "(It) is becoming a more of a bona fide pitch. Command-wise, it's getting over the plate more. For him in spring training, the biggest thing (with his slider) was everything was yanked. Now his slider's in the zone. It's competitive, and guys have to respect it enough to where it keeps them off his fastball."