Chelsea, despite their inconsistent league results, possesses powerful attacking potential and frequently plays high-scoring matches. In the League Cup, such teams typically give rotation players a chance, which often leads to open play with plenty of goals. Cardiff also prefers attacking football at home, especially in cup matches, where the psychological pressure is lower.
An analysis of Cardiff's recent games shows their penchant for high goal totals: three or more goals are regularly scored in their matches. Even against strong opponents, they rarely close down, preferring to attack from the front. Chelsea, on the other hand, having struggled defensively this season, often concede goals, but almost always find ways to score.
Given the cup status of the match, which encourages attacking play, as well as the styles of both teams and their less-than-reliable defenses, it's logical to expect a goal-sharp exchange. The likelihood of the teams scoring more than two goals combined appears high.