Manchester United fans have raised concerns over Harry Maguire being named in their starting line-up for the Champions League Round of 16 second leg clash against Atletico Madrid.Ralf Rangnick opted to deploy the Manchester United captain at the heart of defense against Atletico at Old Trafford, despite the Englishman scoring an own goal in his last appearance.Maguire has struggled to justify his price-tag ever since joining the Red Devils from Hull City in an £80 million deal back in 2019. The Manchester United captain is considered error-prone and is currently enduring a forgetful run of form.Since he has struggled to string together convincing performances, fans are now upset about the fact that Maguire is starting such a crucial knockout game. As soon as the club announced their line-up for the Champions League clash, one fan tweeted:"Such a poor selection, bye CL."Here are some of the other reactions from the fans as we await kick-off of the Champions League clash.Francis@LFCFrancis@ManUtd Maguire starting? Advantage Atletico 12:21 PM · Mar 16, 2022771@ManUtd Maguire starting? Advantage Atletico 😭😭😭Papa Laye@LieSagne@ManUtd Maguire again. Ffs!!12:22 PM · Mar 16, 2022@ManUtd Maguire again. Ffs!!LesMti@les_mti@ManUtd What's Maguire doing here 🤷🤦‍♂️🤔12:28 PM · Mar 16, 20222@ManUtd What's Maguire doing here 🤷🤦‍♂️🤔 https://t.co/XDL0hJxEjlKwesi Adjei𓃵🗨@Official_Kwesi@gyaigyimii @ManUtd João Félix, Harry Maguire and Antoine Griezmann will be the attacking trio against Manchester United. #MUFC12:28 PM · Mar 16, 2022121@gyaigyimii @ManUtd ✅ João Félix, Harry Maguire and Antoine Griezmann will be the attacking trio against Manchester United. #MUFCstan.a@A_stannnn@ManUtd Jesus12:21 PM · Mar 16, 20224@ManUtd JesusBenji_@Benjaminkk3@A_stannnn @ManUtd I feel you12:24 PM · Mar 16, 20221@A_stannnn @ManUtd I feel youRonaldoFan7@ManUtdRonaldo7@ManUtd Maguire starting 12:20 PM · Mar 16, 202236735@ManUtd Maguire starting 😭😭😭 https://t.co/FDMWIXR4igOdunlami Basith@heisOG@Tizbami @ManUtd I'm sorry to break this to you that we are losing with this lineup12:35 PM · Mar 16, 2022@Tizbami @ManUtd I'm sorry to break this to you that we are losing with this lineupNaldo@NaldoUtd@ManUtd 1. Maguire starting and captain 2. Line ups put out in number order instead of formation orderthe 2 biggest reasons why this club is not successful12:31 PM · Mar 16, 2022422@ManUtd 1. Maguire starting and captain 2. Line ups put out in number order instead of formation orderthe 2 biggest reasons why this club is not successfulJohn Terry Wilkinson@johnterry1986@ManUtd Such a poor selection. Bye CL12:30 PM · Mar 16, 2022@ManUtd Such a poor selection. Bye CLEarlier, there were reports of Cristiano Ronaldo wanting to replace Maguire as captain at Old Trafford. But Rangnick has maintained that the defender is his first-choice captain, much to the frustration of some Manchester United fans.Manchester United aiming to join Liverpool and Manchester City in Champions League quarter-finalsBoth Manchester City and Liverpool have secured their berths in the quarter-finals of the Champions League. United are currently tied 1-1 on aggregate with Atletico Madrid and will hope to progress to the last eight of the competition.However, the Red Devils will be well aware of the threat on offer from Atletico. During the first leg in Madrid last month, Joao Felix opened the scoring for the hosts. United then relied on a late goal from Anthony Elanga to salvage a draw.Notably, Bruno Fernandes has recovered from COVID and is back in the starting eleven for the hosts in the second leg. Paul Pogba has surprisingly dropped to the bench.Similarly, former Liverpool marksman Luis Suarez is named only among the substitutes on the bench for Atletico. The Uruguayan is joined by Angel Correa and Geoffrey Kondogbia, among others, as Diego Simeone's other substitue options.