After Shonga's compatriot Augustine Mulenga had put the visitors ahead in the 13th minute, he should have made it 2-0 just before half-time but he dilly-dallied by shifting the ball from one foot to another and eventually the space was closed. His shot was disappointing at it went wide after he initially had a clear sight of goal.
Five minutes into the second stanza, Shonga sprinted clear following an interception but was denied by a save from former Thanda Royal Zulu goalkeeper Siyabonga Mbatha in a one-on-one situation.
Shonga nearly scored in the 63rd minute as he did well to connect with Innocent Maela's cross, but his attempt was foiled by the upright.
He also failed to take advantage from a dangerous delivery across the face of goal from the right by Thembinkosi Lorch afterwards, and landed up being replaced by Meshack Maphangule in the 81st minute in Umlazi.
After the league game, 'Micho' was seen comforting the 21-year-old as they made their way to the tunnel.
The Serbian tactician insists Shonga did everything that was asked of him but it just wasn't his day.
"Justin Shonga, he did very well, he was moving, he was trying," Sredojevic told the media.
"He did three things we asked of him as the striker: to be the first line of defence, try to intercept the balls, to help us enter into attack and to assist or convert the chances.
"He did the hardest parts to come and create the chances. However, he was not converting. Now those are the players we count on. We need to encourage them, we need to give them support, because it could not be that all the hard work that he has done has gone because of missing the chances.
"We are not playing the blame game. These are our boys. We have the highest degree of respect for them, we believe in them, we have trust and confidence in them. We believe that when we give support, the time will come when the same Shonga will pay back with goals scored."
Shonga has scored once this season, from the penalty spot against Highlands Park in the first match of the campaign.
Things have gone better for him on the international front, having netted against Namibia in an AFCON qualifier and in a friendly against Gambia last month.