Manchester United fans were irate with Cristiano Ronaldo's performance during their pre-season friendly against Rayo Vallecano on Sunday (July 31) as he was taken off at half-time.The 37-year-old made his first appearance with the Red Devils since the end of last season. He missed the entirety of their pre-season campaign, citing "family issues."Given the uncertainty surrounding his future, with Ronaldo seeking a move away from Old Trafford, his return to the fold was a welcome sight for the Manchester United fans.However, he was far from returning with a bang. The Portuguese ace dropped a stinker in the first half against the Red Sashes, a team he knows well from his La Liga days. Playing for Real Madrid, Ronaldo came up against Vallecano nine times and netted 12 goals in that period, but there was no such luck for him today.Sportskeeda Football@skworldfootballThe King returns! Cristiano Ronaldo in action in Manchester United's pre-season friendly against Rayo Vallecano.#CristianoRonaldo #ManchesterUnited17The King returns! 👑 Cristiano Ronaldo in action in Manchester United's pre-season friendly against Rayo Vallecano.#CristianoRonaldo #ManchesterUnited https://t.co/mpNwKzVyB5The five-time Ballon d'Or winner looked subdued, mainly because he didn't play a single minute of pre-season coming into tonight's match.His only notable moment was arguably a shot in the 12th minute which he fired over the bar and was put out of his misery at half-time.Young forward Amad Diallo was brought on in place of Ronaldo.Manchester United fans were disappointed with him today, and took to social media to express their dissatisfaction, even making calls to sell him.Here are some of the best Twitter reactions:Chiggy Viggy@IdlySambharAbsolutely love seeing the United fans despising Cristiano Ronaldo right now 1Absolutely love seeing the United fans despising Cristiano Ronaldo right now 😍😍😍ALONDWE ❤️@MAX__DBNGIVE HIM LIFETIME CONTRACT AND SELL RONALDO twitter.com/ManUtd/status/…Manchester United@ManUtdSharp stuff from @AGarnacho7 Which players have stood out for you in the first half? #MUFC3675400Sharp stuff from @AGarnacho7 ✨Which players have stood out for you in the first half? ⬇#MUFCGIVE HIM LIFETIME CONTRACT AND SELL RONALDO twitter.com/ManUtd/status/…victor@ofoe_19We need to sell Ronaldo…I love him but he needs to leave for the sake of team cohesionWe need to sell Ronaldo…I love him but he needs to leave for the sake of team cohesionArief the Wise@EddoyRonaldo looks so unhappy with this team lol just sell him ffsRonaldo looks so unhappy with this team lol just sell him ffstobillions@tobiadebutu1please sell ronaldo my daysplease sell ronaldo my daysChukwuebuka@ChukwuebukaZionDeep down, I wish United sell Ronaldo and sign a younger striker to start developing with the team already.Deep down, I wish United sell Ronaldo and sign a younger striker to start developing with the team already.Gary 🦖🇺🇦@GarysaurusRexRonaldo off? He’s done. #MUFCRonaldo off? He’s done. #MUFCAdamya@adamutd7ronaldo already done1ronaldo already doneZarqon🇫🇷🏴󠁧󠁢󠁥󠁮󠁧󠁿@UtdZarqqRonaldo is done with Chong lmaooo2Ronaldo is done with Chong lmaoooDiallo, who came in place of Ronaldo, was brighter in lesser time as the youngster looks to establish himself in the first team. He scored in the 48th minute to put United in the lead, although the game ended in a 1-1 draw.Fans hailed the 20-year-old for his instant impact while taking a swipe at the former Juventus man:Ten Hag the badly one@ThebaldyoneAmad done more than Ronaldo did in three minutesAmad done more than Ronaldo did in three minutesLB@liamxutdAmad done more in two minutes than Ronaldo did in 45Amad done more in two minutes than Ronaldo did in 45💀S🫡@SLastTryamad done more as a poacher in 2 mins as Ronaldo in the last 2 months1amad done more as a poacher in 2 mins as Ronaldo in the last 2 monthsEdward Harte@EdwardHarte18Amad already done more than Ronaldo 1Amad already done more than Ronaldo 😭😭😭Manchester United face Ronaldo dilemmaRonaldo may have returned to Manchester United but his future remains in limbo.He's also expected to miss their Premier League opener next weekend against Brighton & Hove Albion due to his prolonged absence from their pre-season campaign.The 37-year-old has been linked with some top clubs, but none of them have made any offers. Bayern Munich and Chelsea even played down transfer talks.With just a month left until the summer transfer window to shut, Ronaldo's situation will come increasingly under the scanner.