Anyway Bastian cites a discussion he had with AA who says that we shouldn't expect the team to shift Wells out of CF anytime soon:
In December, during a sit-down with Blue Jays general manager Alex Anthopoulos, Wells' defensive decline was brought up. Anthopoulos was asked if the team had considered shifting Wells out of center field in order to help the outfield defense. Anthopoulos said that was not something the club has discussed.
"We don't have any plans of that at all. We consider him a mainstay in center field," Anthopoulos said. "If Vernon was older, it might be more of a concern. He's still a young guy and he also made some tremendous plays as well. There's times he didn't make great plays, but he also made a lot of tremendous plays. It's just to the point that we expect it, so if he doesn't come up with a ball or comes close, those are the ones that stick out like a sore thumb, because it's rare."