Along with trade-deadline decisions, Nats general manager Mike Rizzo will use the second half to gather information on his 2011 rotation. And, boy, are there plenty of candidates. Only Stephen Strasburg is a lock -- though Livan Hernandez (3.27 ERA) is making a strong push.

The rest of the starters will get a chance to prove themselves. That means Ross Detwiler, Scott Olsen, John Lannan, Jason Marquis and Jordan Zimmermann -- an entire new rotation -- will start at some point. Less certain is veteran Chien-Ming Wang, still waiting to make his first rehab start in Viera, Fla., after 2009 shoulder surgery.

Detwiler (hip surgery) finished his rehab and has looked solid in seven minor league starts (28 2/3 innings, 2.83 ERA, 26 strikeouts, seven walks). Olsen (shoulder) and Zimmermann (elbow) are both technically on rehab stints, but they, too, have looked good. Marquis (elbow) made his first rehab start in Viera on Sunday -- nine full innings with 10 hits and three earned runs allowed. Lannan was the Nats' Opening Day starter but has to pitch his way back to the majors. The results at Double-A Harrisburg have been only OK (1-2, 4.11 ERA) so far.

Meanwhile, J.D. Martin, Craig Stammen and Luis Atilano all have a few more starts in them. So far, Martin (3.35 ERA) has been the most consistent of that group, though Stammen allowed just one run in six innings Sunday.