Defoe has scored five goals in 10 Premier League games this season and, having struck a hat trick in his last outing, is likely to start at the Etihad Stadium.
And Platt, who worked with the 30-year-old during his spell as manager of the England Under-21 team, has hailed the forward's goalscoring instincts.
"He is potent, Defoe will always score goals. He could go six or seven games without scoring but you know if he does there is a glut coming because his stats tell you he scores goals," Platt told reporters.
|11/4||Jermain Defoe is 11/4 to score anytime against Manchester City with Paddy Power|
The former England international also acknowledged Tottenham's other attacking threats, suggesting that goals are always likely when Spurs play.
"You look at them as a collective and you feel as though there are goals in their team," he continued.
"They've got several individuals who can turn a game in an instant and it becomes very difficult because of that. They change their team but they are dangerous.
"What Tottenham have got is over the years, with what Harry [Redknapp] has created and Andre Villas-Boas has added to and developed, a group of young, energetic players that can harm you, [that] can score a goal in an instant."