Dortmund was able to reach the finals last season, but got defeated by Madrid. Dortmund is very experienced in UCL and I believe that they will go far this season. Barcelona is in their best form and one cannot be underestimated, because they have scored a lot of goals this season. This shows that their attack is very active. However, the match is gonna be one of the best in the round of 16.
In the round of 16 of the UCL this season Dortmund will face Lille which is a team that is not so strong in their domestic league so it could be a good opportunity for Dortmund to advance to the last eight of the UCL this season. However, I don't understand why Dortmund are not so good in the Bundesliga this season when Dortmund should be able to put themselves in a better zone than now so they can return to the UCL competition next season.