Out of the 146 goals scored in the 2015 Hero Indian Super League so far, twenty-two have been scored by substitutes. These substitutes have made a profound impression on the game coming off the bench. In fact, the only team not to have a substitute score a goal is Chennaiyin FC. Delhi Dynamos FC, second team to reach the semi-finals this season, and NorthEast United FC currently lead the way for goals scored by substitutes with six goals from 12 and 13 matches respectively. Defending champions Atlético de Kolkata, first to make it to the semis, and Kerala Blasters FC are second with three goals apiece. Following them are FC Goa - the third team to have secured a place in the semis - with two substitute goals. Mumbai City FC and FC Pune City have one substitute goal each.What perhaps is more surprising than the number of substitutes that have scored this season is the massive impact their goals have had on the game. Let’s take a glance at some of the most stunning cameos in Hero ISL 2015 to date.Antonio German and Arata Izumi – It was a tale of two substitutes when Kerala played Kolkata for the second time this season on November 10. Antonio German came off the bench to replace an injured Sanchez Watt and completely changed the course of the match by scoring equalisers twice in the game. His feat, however, was matched by another substitute Arata Izumi who scored twice himself to hand the reigning champions a 3-2 win in Kochi.Gustavo dos Santos – Another player who has got into the habit of scoring after coming off the bench this season is Delhi Dynamos FC’s talismanic Brazilian, Gustavo dos Santos. The pacey youngster has indeed earned Delhi six points this season having netted late winners against hosts Atlético de Kolkata and hosts NorthEast United FC after being thrown on as a substitute.Richard Gadze – Delhi’s Ghanaian striker, Richard Gadze has been one of the impact players of the season. Three of his four goals have come as a substitute this season. The robust frontman has scored winners against FC Pune City and Kerala Blasters FC. He also hammered in a brilliant left-footed effort against Atlético de Kolkata after being summoned off the bench to earn his side a point in a 1-1 draw in Delhi.Simao – Delhi Dynamos FC were at the receiving end against NorthEast United FC in New Delhi. The game was poised on a knife’s edge after a free-kick had been awarded to NorthEast United FC when head coach Cesar Farias started waving frantically at the fourth official, trying to bring on Simao. The Venezuelan’s wish was granted much to the dismay of Silas who was withdrawn for Simao. As it happened, the Portuguese maestro stepped up and curled his free-kick past Antonio Doblas with nonchalance to bring smiles to everyone in the NorthEast United FC camp. The goal helped the Highlanders take one point from the match.Silas – As luck would have it, it was the other way around a week later in Chennai. This time it was Simao making way for Silas. The Portuguese midfielder came on to replace his fellow countryman and kept to the script by netting the winner in a tight game against Chennaiyin FC to hand Farias’ men all three points.One can see how important these substitute goals have been, especially for teams like Atlético de Kolkata and Delhi Dynamos FC. Izumi’s match-winning brace was the beginning of the revival of ATK’s campaign as they took 10 points over the next four matches to seal themselves a place in the semis. Dos Santos’ strike against the Highlanders also led to Delhi’s qualification. Clearly, the role of substitutes in football hasn’t diminished one bit.