11 wins? That's not a lot, especially if you want to call someone undefeated. It's not a bad record but we are comparing it to someone with over 2 times that.
Based on the record and reach I'd say he's an underdog in this fight.
No, Lomachenko is not the underdog in this fight. Actually he was the overwhelming favorite because if you have followed his fights (he is a good amateur background as well winning Golds in 2008 and 2012 Olympics in 2 different weight class). So I would say he is a late bloomer and perhaps pampered that's why on his 3rd fight, he was fighting for the world title and then there's no stopping him. So he may have 11 fights but he is one of the best and I don't think he can be the underdog in his future fights, just saying.