An error from centre-back Raihan Rahman led to Chan Vathanaka's goal in the 72nd minute at the Jalan Besar Stadium, following on from a 1-1 draw against Hougang United on Tuesday night.
"So far it (preparations) have been okay, the boys tried their best and they have never let me down in training," Aide said after the game.
"Today, I think we could have done a little bit better in terms of finishing. They know they need to be sharper and hungrier, and to be more focused in terms of not losing the ball in their own half that can lead to a goal like this.
"I am not too worried about the defeat... I think overall they did well in terms of creating chances, dominating, and the passing is much better than during the game against Hougang."
The former Singapore captain, who refused to blame Raihan for the goal, also stressed the need for quality back-up in his final squad to take to Myanmar.
"For me it’s more of giving those players who lack match fitness a chance to play [and] I am not too worried about the defeat," Aide continued.
"Today it’s not about the starting line-up, we need a good strong bench for this coming SEA Games because we need to rely on these players especially if there are suspensions or injuries.
"For me, what is most important is that I must get the 20 best players fit before we leave so that they can compete."
Cambodia coach Tae Hoon Lee was happy with the victory, with his team having played five games in the last 15 days before this, but claimed it was "just a friendly".
"I think today is a very hard match, but we get one goal [which was] lucky," the Korean said.
"Today we changed the whole team [in the second half] after I asked [permission from] the Singapore federation (Football Association), because our players are very tired now and we have one more game on the 24th, so today we needed to conserve [energy]."
The match on the 24th, this Sunday, will be a senior international between both teams, but only U23 players are expected to feature.
Aide claimed that he was "pretty sure" about his starting line-up for that game, with this defeat helping to give him "a good idea" on who to include in his final squad.
"It’s a good lesson learnt [today] but at the end of the day I am still confident that this team will do well this coming Sunday," he concluded.
The match between Singapore and Cambodia will be played at Hougang Stadium on Sunday, with kick-off scheduled for 7.30p.m. Tickets for the game have already gone on sale.