On September 1, 2007, Morgan made his major league debut for the Pirates against the Milwaukee Brewers as a late-season call-up. On September 14, 2007, Morgan made a catch in Minute Maid Park's center field that proved the difference in a 4–3 Pirates win. Houston Astros manager Cecil Cooper said of the catch "That's probably the best catch I've seen this year.". The catch garnered references to Willie Mays' The Catch on SportsCenter the following day. Morgan also showed his tools against the San Diego Padres on September 20, going 2 for 3 with a triple, two runs scored, two stolen bases, and an outfield assist throwing out Scott Hairston. Morgan's first home run came September 25 against the Arizona Diamondbacks.