While the Phillies' acquisition of Roy Halladay was one of the biggest stories of the baseball offseason, it was hardly a matter of international security.

Halladay's homecoming, however, might be.

The problem arises from a conflict with the annual G-20 Summit, which is scheduled to be held at Toronto's Metro Convention Centre the same weekend Halladay and the Phillies are in town facing the Blue Jays, his former team (June 25-27). According to baseball sources, the convention center's proximity to the Rogers Centre could present a security threat, and Major League Baseball could be forced to alter the schedule of the Phillies-Blue Jays series.