The No. 1 overall pick out of San Diego State University in 2009, Strasburg burst onto the major-league scene in 2010 and won five of eight decisions in 12 starts - striking out 92 batters in just 68 innings - before an elbow injury shut him down prematurely.
He underwent ligament replacement surgery and returned to the mound in the minors, going 1-1 with a 3.54 earned run average across six starts from Single-A to Triple-A, where he struck out 29 batters in 20 1/3 innings.
Strasburg got back to the majors on Sept. 6 against Los Angeles and held the Dodgers to only two hits in five scoreless innings, walking none and striking out four in a game the Nationals ultimately lost, 7-3.
The 23-year-old has never faced the Astros.
On Saturday, Carlos Corporan drove in three runs as Houston downed the Nationals, 9-3. Jason Bourgeois went 3-for-5 with an RBI and a run scored while Chris Johnson and Angel Sanchez each scored twice for the Astros, who had lost six of seven.
Wandy Rodriguez (11-10) gave up three runs on seven hits over six innings to get the win.
Chris Marrero drove in a pair of runs for the Nationals, who have lost three of four.
John Lannan (9-12) was tagged for six runs -- four earned -- on eight hits in just 2 1/3 innings.
For the Astros, rookie righty Henry Sosa makes his seventh big-league start today.
An undrafted free-agent of the San Francisco Giants in 2004, Sosa debuted in the majors on Aug. 10 at Arizona and allowed six hits and four runs over six innings in a 6-3 loss to the Diamondbacks.
He was winless in his initial three starts overall, but has gone 2-1 in three outings since while allowing just four runs on 12 hits in 18 innings.
The 26-year-old, who has never faced the Nationals. has 26 strikeouts and has given up 16 runs in 35 overall innings.
The Astros took two of three over the Nationals on July 18-20, but lost three of four in Washington a season ago.