Burke scored 14 goals and produced 19 assists in the 2011/12 season, as well as winning a host of awards, including the club's Player of the Season.
The Scottish winger's superb 27th minute strike at The Amex on Saturday condemned the league leaders to their first home defeat of this campaign.
"The goal can definitely help his confidence," said Clark. "I said to Chris before the game that he’s just got to keep going.
"His work ethic and his effort have been there, but for whatever reason he hasn’t fired like he did last season. He’d set an unbelievable standard last season and I’ve got total belief in him 100 per cent.
"He gives his all and when you do that the quality is always there and the class is always there. It’s just getting it back out and I certainly saw a spark after he scored his goal at Brighton to see that without a doubt it was coming back."