Bavuma, returning from an elbow that saw him not play any international cricket since June, endured a tough three-match T20 series in India which the tourists lost 2-1.
The Proteas skipper was dismissed without scoring in the opening two matches, which the visitors lost, before ending the series scoring just three from eight balls as South Africa recorded a consolation 49-run win in Indore on Sunday.
Rossouw used himself as an example for his captain to follow as the left-handed batter also failed to trouble the scorers in the previous two games before hitting 100 not out off just 48 balls, his maiden T20I ton that will be a big boost ahead of the global tournament.
Speaking to the media after the victory in the third match, Rossouw said: "Temba's form isn't affecting the team at all.
"We actually talked about it before the game. If someone is going to have a good day, they can carry the weight of someone who's not in great form. We literally saw it.
"It takes just one knock and Temba can be in the form of his life going into the World Cup. We just need to be there for him as a team because every professional goes through this.
"It's about backing him and we do, his ability and his captaincy, we really back him."
Bavuma has another three-match ODI series in India, starting in Lucknow on Thursday, to get some much-needed time in the middle and runs under the belt.
The Proteas will head directly to Australia immediately after the three-match 50-over series.
"As a professional sportsman, you're going to have bad times," Rossouw added. "It's about backing yourself, having belief in your ability.
"No matter the type of form you're in, your confidence needs to be high because those are two separate things.
"I actually had a chat to one of the assistant coaches about form and confidence and that's something I really believe in."