The holding midfielder took Jose Mourinho's place at a press conference and highlighted the importance of the upcoming cup encounter
The midfielder took head coach Jose Mourinho's place at Tuesday's press conference as the Portuguese opted to sit out, and Alonso expects a difficult second leg after Madrid lost the away game 2-1 before the winter break.
"We know how important the match is, it will be like a final. We hope the team plays well and that the crowd gets behind us. We are feeling good and I hope that we can keep this positivity from the start of the year," Alonso said at a press conference.
"We have to set out to win the match. Trying to keep a clean sheet in this competition gives you the advantage. Celta are playing well. I do not think it will be an easy match, but if we connect with the people we have a good chance of getting through and we are confident about qualifying."
Wednesday's encounter is scheduled to kick off at 21:30CET.