The Nationals activated pitcher Casey Janssen from the 15-day disabled list, per Nationals.com.
Janssen has been out all season with shoulder inflammation. He made six minor league rehab appearances in Class A and Double-A.
The team also placed LHP Sammy Solis on the 15-day disabled list, retroactive to May 18. Solis is suffering from shoulder inflammation. He is 1-0 with a 5.00 ERA this season.