Nick Swisher Says Phillies Wouldn't Be In World Series With Joe Girardi

Nick Swisher says the Phillies would not be two games away from a World Series title if they had kept Joe Girardi ... telling TMZ Sports the team's new manager, Rob Thomson, is the biggest reason for Philly's success this year.

"If it was Joe Girardi in this position," the former Big Leaguer told us, "I don't think Philly would be in this spot."

The Phils had started the season with Girardi at the end of the bench -- but put him on ice back in June after a disappointing 22-29 start. Thomson then became the interim manager, and the team took off.

Swisher told us he believes none of that ensuing success was a coincidence ... saying Thomson -- who was one of the outfielder's coaches during his time with the Yankees -- is just that good of a honcho.

"Rob Thomson has given that team the freedom to be themselves," Swish said. "He has given them the freedom to go out and play with freeness and be open and authentic."

Swisher clearly believes the guy and his team can close out the Astros this week, too ... telling us with the talent they have, and the fan support in Philly -- two more wins shouldn't be hard to come by.

As for what Swisher's been up to outside of watching this year's Fall Classic -- he's actually launched a new podcast, "The Nick Swisher Show," where he'll be interviewing people from all different walks of life about the importance of positivity.

"On this podcast, man," he told us, "we jump in!"