Strasburg overwhelmed hitters in Double-A and Triple-A. His combined stats: 7-2 with a 1.30 ERA with 65 strikeouts and only 13 walks in 55 1-3 innings.
Right-hander Jeff Karstens (1-1), making his fifth start of the season, will oppose Strasburg.
A day before the Nationals' No. 1 pick from 2009 was scheduled to make his major league debut, the team added what it hopes will be another future star.
The Nationals took 17-year-old Bryce Harper with the No. 1 pick in the 2010 MLB draft on Monday night, adding the phenom a year after they took pitcher Stephen Strasburg first overall.
Like Strasburg, who will start for the Nationals on Tuesday night, Harper was the subject of an overwhelming media buzz during his amateur career. He got his GED and enrolled at the College of Southern Nevada so he could be eligible for the draft a year early, and, like Strasburg, he could command record-setting dollars from the Nationals.
Estimates have placed a possible Harper signing bonus at anywhere from $8 million to $16 million, and there's a decent chance his bonus would surpass the $10 million given to Mark Teixeira in 2001 as the most ever awarded to a position player. It seems farfetched Harper would get more than the $15.1 million total contract given to Strasburg in 2009, simply because he's not likely to get a major league deal.
The Nationals said they will move Harper, who was primarily a catcher at Southern Nevada, to the outfield. General manager Mike Rizzo said Harper's offense is far ahead of his defense, and moving him from the catcher position will help him reach the majors more quickly.
--RHP Stephen Strasburg will make his major league debut on Tuesday and will be limited to no more than 100 pitches against the Pirates. Strasburg, who will be officially called up from Class AAA Syracuse (N.Y.) on Tuesday, had a combined 7-2 record and 1.30 ERA at Syracuse and Class AA Harrisburg (Penn.).
--C Ivan Rodriguez played for Class A Potomac (Woodbridge, Va.) on Monday night, catching for the team in a rehab assignment the Nationals are hoping will have him back in the majors for Stephen Strasburg's big-league debut on Tuesday night. Rodriguez has been out since May 22 with a strained lower back.
--OF Roger Bernadina has six hits in his last 17 at-bats and reached base four times in the Nationals' 5-4 loss to the Reds on Sunday. Bernadina has received most of the playing time in right field for the Nationals in the last several weeks, though he is still not starting against left-handed pitchers.
--RHP Matt Capps has blown four of his last six save opportunities, but manager Jim Riggleman said he hasn't considered "anything like" removing Capps from the closer's role. Capps converted his first 16 save opportunities this season. He said his struggles have come primarily from an inability to keep his slider down.
--INF/OF Mike Morse had his second big pinch hit in less than a week on Sunday, driving in two runs with a ninth-inning double against the Reds. Morse started a ninth-inning rally on Thursday in Houston that led to the Nationals tying that game. He was slated to be the team's primary right-handed option in right field but never got a chance at regular playing time after straining his left calf on Opening Day.
BY THE NUMBERS: 3 -- Saves closer Matt Capps blew in the last week. Capps started the year 16-for-16, and still leads the majors with 18 saves, but has blown four of his last six save opportunities.
QUOTE TO NOTE: "We've had so many ridiculous errors; you use the word 'unconventional.' ... I'm off that subject. I know what we do to prepare. And I know we prepare well. If we don't get the results, we can look ourselves in the mirror and say, 'We do everything we can to play better, and if it doesn't work, it doesn't work.'" -- Nationals manager Jim Riggleman, on his team's major league-leading 53 errors this season. The Nationals have talked all season about their improved defense, but a recent run of miscues in the field have contributed to a 7-16 stretch.