All four outfielders - including Eric Sogard on both occasions - played deep. The shortstop also shifted to the right of second base, leaving the left side of the infield completely vacant.
"I've never seen that. That's intense," Harper told The Associated Press. "If they start playing ball like that, it's definitely different.
Four-man outfield alignments are rare but not unheard of; Texas Rangers slugger Joey Gallo has faced them on multiple occasions.
Blue Jays manager Charlie Montoyo, entering his rookie campaign as an MLB skipper, told reporters his team would deploy unusual defensive alignments in the final weeks of spring training and that he plans to use them during the regular season, according to Gregor Chisholm of MLB.com.