Harrisburg's Rivero strong in second start off DL

Making his second start for Double-A Harrisburg since returning from a three-month-long stay on the disabled list due to an arm injury, left-hander Felipe Rivero, the Nationals' No. 17 prospect, threw five scoreless innings Wednesday. It wasn't enough for a victory, however, as Portland came back to defeat Harrisburg, 5-3.

Rivero struck out six batters, walked two and held the Sea Dogs to one hit. He threw 70 pitches and matched his longest start of the season.

Before his injury, Rivero opened the season with Harrisburg. He has made eight starts for the Senators, going 1-6 with a 5.18 ERA. He has struck out 25 batters and walked 16 in 33 innings.

Rivero was part of the package the Nationals acquired from the Rays in February in exchange for right-hander Nate Karns. Also included in the deal was outfielder Drew Vettleson, who went 0-for-4 with four strikeouts Wednesday for Harrisburg. The Nationals' No. 15 prospect also was limited by injury this season (a broken hand) and is hitting .227/.260/.409 in 64 games with the Senators.

-- Teddy Cahill