(CBS) Despite Nationals right-hander Stephen Strasburg not taking the ball for his team in an elimination game against the Cubs on Wednesday because he’s ill, Nationals general manager Mike Rizzo defended the competitiveness of his $175-million ace.

“He is attempting to put his balls on the line,” Rizzo said on 106.7 The Fan in Washington D.C. on Wednesday morning ahead of the after Game 4 of the National League Division Series at Wrigley Field. “He went out and threw a bullpen and said to Mike Maddux, our pitching coach, ‘I’m going to give you everything I have, I don’t know how much it is.’ We made the decision that we want a 100 percent Tanner Roark over a depleted Stephen Strasburg.”

After Tuesday’s scheduled Game 4 was called off because of rain, confusion reigned regarding the Nationals’ starter for Wednesday. Most expected Washington to turn to Strasburg, who would be on full rest. But manager Dusty Baker cited “mold” in the Chicago air, the weather and the air conditioning at the team’s hotel as reasons for why Strasburg and several of his players had come down sick.

Right-hander Tanner Roark (13-11, 4.67 ERA) will start Game 4 as originally scheduled. The Cubs lead the series 2-1 and will turn to right-hander Jake Arrieta.

Baker also initially mentioned that illness aside, the routine-oriented Strasburg threw a bullpen session earlier Tuesday and thus his arm wouldn’t be physically prepared to pitch Wednesday. That raised eyebrows, as the Nationals were aware of the forecast and would’ve been short-sighted to have Strasburg engage in an activity that would prevent him from starting a day later.

But later, Nationals officials clarified that Baker misspoke and that Strasburg actually threw his bullpen Monday ahead of Game 3.

And then Rizzo was left to answer questions Wednesday morning.

“This isn’t about Stephen Strasburg pitching through adversity,” Rizzo said on The Fan. “This is about winning Game 4.

“He looked bad, he looked under the weather, he looked sick. He threw his bullpen and was just very, very depleted, no energy. He was just toasted really, really fast in the bullpen. He had no endurance. To us, that’s the biggest key. He didn’t improve, he got worse (Tuesday) as far as how he was feeling and we just decided to get with a guy who has won 15, 16 and 13 games in the big leagues for us and is a reliable starter. We’d rather have Strasburg on full, five days rest at 100 percent feeling great, but that’s not the case.

“We feel that with Tanner pitching the way he’s pitching, at full go and 100 percent, prepared and focused and set to pitch this game throughout the playoffs, we feel that’s our best chance to win Game 4.”