Ryan Vogelsong said he “really doesn’t have a good explanation” for why he’s struggled this season both before he missed three months with a fractured finger and now when he's hit the wall in his last two starts.

Others have filled the void by blaming the World Baseball Classic for starters.

Vogelsong acknowledged to me that he has wondered the same thing: Did his participation in the March tournament especially coming off a World Series drive take too much steam out of him?

And if so does he regret playing for Team USA?

“I don’t know if I regret doing that as much as I regret swinging at a two-seamer that was going to hit me” said Vogelsong referring to the Craig Stammen pitch that crushed his pinkie finger on May 20.

There’s no doubting the cause and effect of that swing. The WBC is a murkier issue – both for him and other participants including Jeremy Affeldt and Marco Scutaro who have dealt with injuries all season. Pablo Sandoval Santiago Casilla and Angel Pagan lost time to the disabled list too.

In fact of the eight Giants who participated in the tournament only Scutaro and Jose Mijares have avoided the disabled list – and Mijares hasn’t exactly had the strongest season. Even minor league catcher Tyler La Torre who played for Italy ended up missing time.

Correlation does not imply causation as you’ll learn in any intro to statistics class. But you can bet Giants officials have done a fair share of correlating this season.

And Vogelsong wonders too.

“I definitely have some questions whether the WBC hurt me or not” said Vogelsong who had electric stuff in his two starts for Team USA. “But I doubt myself more for swinging at that pitch because that’s something I could have controlled.

“It’s just been hard for me to explain to you what it's like when you’re rehabbing in the middle of a season. It’s not easy to do. That has no effect on making the bad pitches I did (Tuesday) night. But when you’re trying to get healthy it definitely throws a wrench into it and you’re doing things you’re not used to doing.”

His pitches aren’t doing what they’ve done the previous two seasons -- and that was the case before the injury too. In nine starts before going on the DL Vogelsong had a 7.19 ERA and opponents were hitting .318 off him. He had one quality start out of nine – a far cry from a year earlier when he threw quality starts in 18 out of 19 outings in the first half.