When will the Nats go to a fifth starter?

Nationals reliever Joel Peralta is excited about the opportunity to get to pitch at the Major League level again and certainly seems ready for the challenge. While at Syracuse, Peralta dominated at throwing strikes and getting the first batter he faced out. Peralta got the first man out 20 of the 26 chances at Triple-A. It continued Tuesday night in his first Nats appearance when he induced a double play off the bat of the Royals Jose Guillen. The 5'11", 195-pound right-hander from the Dominican Republic struggled with Colorado last season, going 0-3 with a 6.20 ERA. Yet, he dominated at Triple-A Colorado Springs with a 6-0 record. This season, he was the closer for Syracuse, notching 20 saves and a 1.08 ERA. Peralta hopes to write a new result at the big league level this time around. Peralta told me he got a chance to see what Stephen Strasburg can do as a pitcher in Syracuse and came away pretty impressed. "(Strasburg) is not from this planet" with the way he can pitch at such velocity with that kind of control." With Peralta added to the fold, it is an important week for the Nats pitching staff. Peralta is capable of being added to the Drew Storen, Tyler Clippard and Matt Capps late inning arsenal, because he was the closer for the Chiefs. Strasburg is scheduled to pitch again on Monday on five days rest instead of five games rest, so the Nats can buy some time before they will need a fifth starter again in the rotation, if they choose to go that direction. There are some strong candidates for that role in the minors. Shairon Martis has gone 4-3 with a 3.15 ERA last 10 in the minors. Craig Stammen came within 1-out of a no-hitter last Friday and is 2-0 with a 2.25 ERA in 3 starts. Ross Detwiler has made a pair of shortened rehab starts for Harrisburg and has a 0-0 record with a 1.17 ERA. Now that he is on the full fledged active Double-A roster, expect him to go, as he told me last week, from 70-75 pitches to 80-90 pitches in the next couple of outings. Further, Opening Day starter John Lannan makes his first start for the Senators tonight as he attempts to get back to the Nats as soon as possible. That is why it is imperative for guys like Miguel Batista and Tyler Walker to pitch well in the bullpen, and for Luis Atilano and tonight's starter J.D. Martin to maintain what they have done in their two most recent starts. Either way, you could easily see a Stammen, Martis or a Detwiler reappear with the Nats when the call is necessary for that fifth starter. That is why you want to be pitching your best once the record stops in musical chairs.