Manchester United fans were not happy with Erik ten Hag's decision to substitute Cristiano Ronaldo in the 72nd minute against Newcastle United. The forward struggled to secure an impressive outing, getting caught offside on a number of occasions and receiving a yellow card for his struggles. However, Ronaldo notably scored what seemed to be the only goal of the game, which was, however, chalked off for offside.The United fans believe that their 37-year-old marksman should have been kept in the game, rather than getting substituted. Taking to Twitter to share their opinions, they slammed the manager's decision, while Ronaldo was understandably displeased as well.Here is a selection of tweets from the enraged Old Trafford faithful:Mannie 🇳🇬@simonmanasseh88Rashford for Ronaldo is a very stupid sub decision. If Ten Hag knows he wouldn't be playing Ronaldo he should've sold him.1Rashford for Ronaldo is a very stupid sub decision. If Ten Hag knows he wouldn't be playing Ronaldo he should've sold him.Benji🔥@Benthegod20ETH shouldn't have sub. Ronaldo. He's an experienced player that scores match winners. Ole made this same mistake once. Ronaldo can't miss that Rashford miss twitter.com/premierleague/…Premier League@premierleagueFULL-TIME Man Utd 0-0 NewcastleBoth goalkeepers were tested and Joelinton twice struck the woodwork, neither side could find a way through#MUNNEW26251FULL-TIME Man Utd 0-0 NewcastleBoth goalkeepers were tested and Joelinton twice struck the woodwork, neither side could find a way through#MUNNEW https://t.co/HO20X0twsvETH shouldn't have sub. Ronaldo. He's an experienced player that scores match winners. Ole made this same mistake once. Ronaldo can't miss that Rashford miss twitter.com/premierleague/…M I K E ©@mikemuhimaETH's lack of subs needs to be called into question today. Fred's little relevance to the team ended when Ronaldo went off, but for some reason he stayed on the entire fuckin time.62ETH's lack of subs needs to be called into question today. Fred's little relevance to the team ended when Ronaldo went off, but for some reason he stayed on the entire fuckin time.Huz@HuzCW1We would have been celebrating a Ronaldo's last minute winner right here only if Ten Hag didn't sub Ed him off3We would have been celebrating a Ronaldo's last minute winner right here only if Ten Hag didn't sub Ed him off https://t.co/RWXpULs8JtCristiano_Culture@Cristiano7_CultRonaldo better be in Ten Hag's office tomorrow morning because that was disgraceful from the manager to sub him off when you need a goal3Ronaldo better be in Ten Hag's office tomorrow morning because that was disgraceful from the manager to sub him off when you need a goalDAIO@TheifedayoRonaldo scores this chance but the coach decide to sub him off5Ronaldo scores this chance but the coach decide to sub him off https://t.co/5RTpW9JGU0The Portuguese star was noticeably unhappy with the decision after he saw his name come up. He was seen shaking his head while walking off the pitch and muttering. The forward kept shaking his head even after he had taken his seat on the Manchester United bench, while the game progressed.Cristiano Ronaldo slumps in poor performance as Manchester United fail to beat Newcastle UnitedThe most notable attacking moments of the game came from the Magpies, who took the game to the Red Devils from the onset. While Cristiano Ronaldo struggled to stay onside against a Newcastle defense that were prepared to defend against him, Newcastle had no such trouble.The first half saw the hosts struggle to secure major chances, as they failed to find important passes through the visitors' defense. However, Newcastle were likely the better side by the end of the first half, having enjoyed better chances in front of goal.Joelinton had two impressive chances to secure a goal for his side, notably hitting two headers at the crossbar in quick succession. The Magpies also had other key chances that might have seen off the Red Devils, but a poor clinical output kept the scoreline unchanged.In the second half, there were a number of vital chances for Manchester United, with Jadon Sancho notably getting tackled in the box. There was a penalty shout, but a VAR check ensured that the Red Devils did not have a chance to convert from the spot.The drab draw, which saw sub-par performances all round, did little to keep the home fans in the stadium before the match ended. Notably, empty seats were seen, with fans exiting Old Trafford five minutes before the match ended.