Liverpool survived an almighty scare in their Champions League semi-final second leg tie against Villarreal at El Madrigal on Tuesday, 3 May. They came from two goals down on the night to win the match 3-2 and win the tie 5-2 on aggregate.Jurgen Klopp's side put in one of their worst performances of the season in the first half. Goals from Boulaye Dia and Francis Coquelin canceled out the Reds' 2-0 victory at Anfield last week.However, the Premier League side eventually got their act together in the second half. Goals from Fabinho, Luis Diaz and Sadio Mane secured their place in the final on 28 May at the Stade de France in Paris.Liverpool FC@LFCPARIS HERE WE COME 265346153PARIS HERE WE COME ✊🔴 https://t.co/MpbZuOfP0WThe Reds had to rely on some questionable goalkeeping from Villarreal goalkeeper Geronimo Rulli. However, the Reds' fans were less than impressed with their defensive efforts in the first 45 minutes.Many supporters directed the blame towards right-back Trent Alexander-Arnold. The right-back was hopelessly beaten in the air at the back-post to allow Coquelin to head home Etienne Capoue's cross just before the break.The full-back then set up Diaz's goal with a beautiful left-footed cross in the second half.Still, the Reds' fans took to Twitter to vent their frustrations, with many believing the 23-year-old isn't good enough defensively. Here are some of their reactions:FSG OUT@ShaunlfcTTrent doesn’t even look at Coquelin coming into the box, gives him a free run and header. Atleast he can do a 50 yard switch though556Trent doesn’t even look at Coquelin coming into the box, gives him a free run and header. Atleast he can do a 50 yard switch thoughIRREPLACEABLE@Laxix6Even as a Loserpool fan, you should know that Trent can’t defend. He isn’t good enough.7420Even as a Loserpool fan, you should know that Trent can’t defend. He isn’t good enough.Alfonso♨️@PrimealfonsooWe liverpool fans are embarassing How can we even compare Trent Alexander Arnold to world class players like Reece James?Sorry / every liverpool fan9812We liverpool fans are embarassing How can we even compare Trent Alexander Arnold to world class players like Reece James?Sorry / every liverpool fanGraeme Kelly@GraemeKelly1Fuck off Trent. I knew everyone talking about Paris would bite us on the arse. Get fucking Henderson on. #LFC23813Fuck off Trent. I knew everyone talking about Paris would bite us on the arse. Get fucking Henderson on. #LFCDevan@RB_07FtboITrent is so embarrassing man. Can’t be doing this at the top level. Was at fault for City’s 2nd at the Etihad as well406Trent is so embarrassing man. Can’t be doing this at the top level. Was at fault for City’s 2nd at the Etihad as wellGini@Giniszn5We tried to defend Trent time after time after time man I can’t do this anymore171We tried to defend Trent time after time after time man I can’t do this anymoreKlopp previously defended Liverpool right-back Trent Alexander-ArnoldThe England right-back has been a key part of Klopp's defense for a number of seasons now, with May's final being Alexander-Arnold's third in five years.The boyhood Liverpool fan has made 41 appearances for the Reds this season, scoring twice and providing 18 assists. However, the Liverpool academy graduate has been accused previously of not being the greatest when it comes to the defensive side of the game.However, Klopp slammed critics of the full-back in an interview with Sky Sports in mid-March.The German said via The Mail:"If anybody says that Trent cannot defend then they can come to me and I'll knock them down. I cannot hear that any more, I don't know what more the boy has to do."Dubois@CFCDUBoisTrent Alexander-Arnold when asked to defend60971063Trent Alexander-Arnold when asked to defend https://t.co/mD3Nvp0bAM