Chicago Cubs' fans, players and coaches alike were left holding their breath on Friday night after right fielder Jason Heyward was forced to leave the game after colliding with the right-field wall at San Francisco's AT&T Park. Heyward had just completed a remarkable diving catch in what's known as Triple's Alley, surely taking away at least three bases from Giants' leadoff hitter Denard Span. However, his momentum carried him directly into the wall, forcing his upper body to bend awkwardly. [Elsewhere: Own Bryce Harper's jersey from dugout fight with Jonathan Papelbon ] The outfield wall is mostly padded in San Francisco, though there's a slight opening at the bottom where Heyward hit. That didn't help matters, but given the angle and the force there was nothing Heyward could do to prevent his body from being jarred by the impact. Heyward remained on the ground for several minutes as his Cubs teammates surrounded him and the team's athletic trainer tended to him. He was able to walk off under his own power, which was a good sign. For now, the Cubs are calling it a right torso or abdominal injury, but something more official should come out soon. Jason Heyward is under evaluation...