The right-hander, out since exiting his start on June 8 with right shoulder inflammation, pitches the opener of an important three-game series against the Atlanta Braves.
With 66 games remaining, the Nationals (48-48) are 5 1/2 games behind first-place Philadelphia in the NL East and five games behind the Braves.
Since Strasburg's departure, rotation members not named Max Scherzer have struggled and the team's starters now have a 4.00 ERA for the season.
Strasburg (6-6, 3.46 ERA) will make his 30th career start against the Braves, his most against any team. He is 11-10 with a 3.85 ERA against them with 193 strikeouts in 156 2/3 innings. Freddie Freeman is hitting .371 against Strasburg with four homers and 10 RBIs.
Washington is also expected to get first baseman Ryan Zimmerman (oblique and hamstring injuries) back in the lineup for the first time since May 9.
The Nationals are 7-13 since June 20, but neither the Braves or Phillies have been able to create a huge gap in the division.
"I think, as a team, I think you know we can do a lot better as a group, as a whole," Bryce Harper told MASN.com. "And personally, of course, I want to be hitting .300 and driving in runs and stuff like that.
"I feel like whatever I've got at the break, I'm fortunate to be there, and I think, as a team, we need to keep going and keep grinding. Five and a half at the break, we're fortunate to be there."
Perhaps Harper's success in winning the Home Run Derby will carry over into the second half. The theory goes that taking part in the event can wreck your swing, but Harper entered the break with a .214 average and just five homers since June 1.
With the trade deadline fast approaching, the Nationals could try to add a starter or possibly a catcher.
The Braves (52-42), one of baseball's pleasant surprises in the first half, limped into the All-Star break as well, losing 8 of 11. Atlanta may also be looking to add a piece over the next few weeks, though All-Star and MVP-candidate Freeman likes the group they have.
"A lot of people have talked about our last couple weeks and how we haven't played like we have," Freeman told the Atlanta Journal Constitution. "You start getting, 'They need this because of this,' and I'm like well, hold on. Look at our first three months. We played really good with the group we have.
"There's a two-week stretch every single year where you don't play as good. I feel like the All-Star break came at the right time. But I like our team."
Atlanta right-hander Anibal Sanchez (4-2, 2.60 ERA) looks to continue his career dominance against the Nationals when he pitches the opener. The 34-year-old allowed two earned runs over 12 2/3 innings over his last two starts.
He picked up a no-decision against the Nationals on June 3 after allowing two unearned runs on two hits over seven innings. In his career, he's 9-1 with a 2.01 ERA in 24 games, 23 of them starts.