Some supporters groups have urged fans not to attend the match at St. James' Park as a protest against owner Mike Ashley.
But Bruce thinks the Toon faithful will be out in force to cheer on their team.
He told talkSPORT: "I am convinced that come the first game they will be behind us.
"Newcastle fans will be there cheering on their team, unwavering in their support, when the season starts.
"Sometimes it can be blown out of proportion. I saw a demonstration the other day with 12 people in it.
"If results go your way and it is positive, everything is OK."