They're undervalued, especially given their Serie A performance. The odds now? They favour Leverkusen too much. Leverkusen is solid, while Roma has X-factor. They can activate it as needed. Roma is a good bet. They've surprised big teams and have good odds. Never underestimate Italian teams - they can perform in important occasions. Roma winning or both teams scoring are possibilities. Consider and investigate, but those chances dont reflect Roma's potential.
Every competition has surprises that are difficult to predict, even though any club looks strong, it can definitely lose and this case does not only happen in the EPL but also in the Champions League which we can use as an example, like Barcelona was very favorite but apparently failed and after that PSG was favorite. also lost in yesterday's match.
Cases like this are just an example of the fact that the strongest club is not guaranteed to win and the weak club is also not guaranteed to lose.
Roma while competing at home still has the opportunity to get a higher score than Leverkusen to secure the second leg of the match.
If Roma fail to provide resistance, I am sure Leverkusen will take advantage of this condition.