Bryce Harper will try to continue doing his best to soften the blow of the missing ace.
Lannan and Harper look to keep the NL East leaders rolling and beat the New York Mets on the road for a franchise-record eighth straight game Wednesday night.
The Nationals (88-54) are seemingly headed for the postseason for the first time since 1981 when they were the Montreal Expos, so their decision to shut down Strasburg for the rest of the season has drawn national criticism and scrutiny. They made the move to better preserve his arm following his first full season after undergoing Tommy John surgery two years ago.
The controversial move leaves Washington without its ace, who is 15-6 with a 3.16 ERA with 197 strikeouts. His final start was supposed to be in the finale of this series, but manager Davey Johnson shut him down after he allowed five runs in three innings Friday against Miami.
Lannan (2-0, 3.46 ERA) was recalled from Triple-A Syracuse on Saturday to face the Mets (65-77). He went 3-1 with a 1.63 ERA and two complete games over his last five starts with Syracuse after beating Miami in his most recent outing for the Nationals on Aug. 3.
"Obviously it's different, I'm not throwing in front of 200 people here, so the adrenaline is probably more up here than it is down there," Lannan told the team's official website. "It's just something that happens. It feels great, because I haven't been in a lot of pressure situations down there, but I'm ready."
Lannan isn't expected to be part of Washington's playoff rotation, but the left-hander will try to help the club to its 12th victory in 15 games.
He's 3-1 with a 1.95 ERA in his past five starts against the Mets, but hasn't faced them since a win at Citi Field on April 10, 2010.
The Nationals are 13-4 versus New York this year, winning seven in a row as the visitor to match the team record set from 1979-80.
Harper is 7 for 19 with two doubles, one homer and four RBIs in five visits to Flushing, and continued that impressive production with his first four-hit game while driving in a run in Tuesday's 5-3 victory.
The 19-year-old rookie phenom is hitting .389 with six homers, 12 RBIs and 15 runs in 14 games.
Jayson Werth, batting .354 in 12 games, is also pounding Mets pitching at a .414 clip in eight contests after going 2 for 2 with three walks Tuesday.
New York has lost 21 of 25 at home, including the first five of this six-game homestand while scoring nine runs and batting .204. The Mets haven't scored more than three runs in a club-record 12 consecutive home games, losing 10.
Similar to Strasburg, rookie Matt Harvey (3-4, 3.04) is expected to be shut down after reaching his innings limit, which he's on target to hit for his next start.
"Those aren't my calls, whatever they decide is fine," Harvey told the team's official website.
The 23-year-old right-hander is scheduled to face the Nationals for the first time, and he's 0-1 with a 2.25 ERA in two home starts while getting backed by one total run.
Harvey didn't get any support at St. Louis on Sept. 4, allowing all three of his runs in the second inning and pitching five overall in a 5-1 defeat.