Before that play, Solis was a dominant reliever. He hadn't allow a run in his last 11 appearances spanning 15 innings.
Solis felt if he didn't allow the walk to Russell, the Cubs might not have scored.
"It [stinks] to come out on that end. I have to execute pitches better," Solis said. "I left a couple of them up the middle. Leadoff walk doesn't help. It's on me. I'll get them next time. With the Cubs, you can't give them any kind of edge."
The fact that manager Dusty Baker even had Solis pitching in such important innings late in the game would have been difficult to imagine when he was first promoted from the Minors to replace the injured Matt Belisle in late April. But Solis started the game with a 1.42 ERA, and he has pitched his way to a prominent role in the Nationals' bullpen.
With closer Jonathan Papelbon on the disabled list, and Baker reluctant to name a full-time closer on Tuesday, perhaps Solis has worked his way into a role as a late-innings option for the Nats.
"Obviously, it's great [when] a manager and pitching coach have confidence in you," Solis said. "Obviously, the pressure of the games is a lot, but I think that's what we thrive on, so I'm happy to be in there. I'm glad to be in there, and sometimes it works out, sometimes it doesn't, but I got to go back to the drawing board and be ready to go tomorrow."
Baker didn't seem concerned that Solis gave up the game-winning run against the Cubs and expressed his confidence in Solis.
"[Solis has] been great for us," Baker said. "He just made one bad pitch. He got the slider up, and that was really the only bad pitch he's made in -- I don't know how long. Almora could've popped it up. He didn't miss it."
Bill Ladson has covered the Nationals/Expos for MLB.com since 2002 and writes an MLBlog, All Nats All the Time. He also can be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.