Major League Baseball is investigating an incident in which Toronto Blue Jays outfielder Kevin Pillar appeared to scream a homophobic slur after striking out against Atlanta Braves pitcher Jason Motte. Pillar's apparent use of the slur on Wednesday was in response to a quick pitch from Motte, with the benches emptying after the incident.Commissioner Rob Manfred confirmed on Thursday that the league is looking into the matter."We were made aware of an allegation along the lines of what you've described, and we're in the process of trying to gather the facts as a prelude to determine whether and what discipline is appropriate," Manfred said.Pillar admitted to the Toronto Star after Wednesday's contest that his in-game comment was "immature, it was stupid, it was uncalled for."... It's part of the game, it's just, I'm a competitive guy and heat of the moment. Obviously, I'm going to do whatever I've got to do to reach out and apologize and let him know he didn't do anything wrong, it was all me."The Blue Jays suspended shortstop Yunel Escobar for three games after he wrote a homophobic slur in Spanish on his eye black in 2012. Escobar was ordered to undergo sensitivity training and his three-game salary was donated to the "You Can Play" project, which works to ensure athletes are treated the same regardless of sexual orientation.The tension in Wednesday's game didn't end with Pillar's outburst, however. The benches emptied again in the eighth inning after Toronto's Jose Bautista emphatically flipped his bat following a home run, with second baseman Jace Peterson saying something to the slugger as he rounded the bases."That's something making the game tough to watch," Braves pitcher Eric O'Flaherty said of Bautista's celebration. "It's turned into look-at-me stuff. He hit a home run with (the Braves holding) a five-run lead and throws the bat around. I'm just tired of it. I've seen it from him enough."