The two sides will meet in Budapest on Wednesday for the second-leg of their Champions League last-16 tie.
Leipzig are down 2-0 on aggregrate, but Angelino thinks he can help exploit Alexander-Arnold's 'weakness'.
"It was tough because I thought we played a really good match," Angelino insists.
"We were a few times behind their full-backs. Alexander-Arnold on the ball is unbelievable but he is too offensive. But that is his best [quality] so we have to exploit the weakness and hopefully we can get a few more chances like we did in the first game. That was our mistake that we did not put them away.
"We could have put some pressure on them [by] scoring some of the chances we got. We felt we gave them two mistakes and a team like Liverpool, with the quality they have got, they kill you if you give them just a little bit.
"But we are positive because we played a strong match. If we don't make mistakes and we put our chances away, it can turn around, the situation. There is still 90 minutes to go and we will be focused and ready to go again. The pressure, I would say, is more on them than us. We are the underdog so we go from behind."