Former Manchester United midfielder Luke Chadwick has insisted that Cristiano Ronaldo was frustrated following their 1-1 draw against Burnley in the Premier League on Tuesday. The five-time Ballon d'Or winner was left on the bench and brought for the last 20 minutes of the game.Chadwick graduated from the Red Devils' youth academy and made 38 appearances for the senior side. He claimed the frustration of the Portuguese was quite natural.The 41-year-old also insisted that Ronaldo is ''one of the best players that has ever lived'' and should start every game.Chadwick told Caught Offside:"I'm sure Cristiano Ronaldo's not happy. He's going to want to start every game. He won't see it as him being a player who's getting a bit older and needs a bit more rest. He's one of the best players that's ever lived, and he'll feel he should start every game. I'm sure he'll be frustrated, he had a couple of opportunities but didn't have a huge impact."Sky Sports News@SkySportsNewsCristiano Ronaldo has become disillusioned with life at Man Utd and is plotting showdown talks with his agent over his future, according to newspaper reports 🤯3:24 AM · Feb 11, 20223291512Cristiano Ronaldo has become disillusioned with life at Man Utd and is plotting showdown talks with his agent over his future, according to newspaper reports 🤯 https://t.co/KuOG8UQOURThe Portuguese made a sensational return to Manchester United last summer from Juventus. But he has often cut a frustrated figure during his second spell at the club.Chadwick also pointed out that the Portuguese will forever be a "living legend" at Old Trafford, regardless of how things have gone following his return to the club.Chadwick said:"I don't think there's anything to worry about in terms of the fans' feelings about Ronaldo, he's a living legend at the club. He plays on the edge and if he's unhappy he's not afraid to show it, so I don't see it as a massive problem."He added:''He's a born winner, he wants to win, so there's probably frustration at not starting the game and then how the game's gone, but you wouldn't want to change anything about him.''Can Cristiano Ronaldo bring the glory days back at Manchester United?This is not the first time the striker has looked visibly frustrated at Manchester United. He also showed his anger at being subbed in a 3-1 win over Brentford in January.At 37 years of age, it is needless to say that the Portuguese is not the player he used to be. But he still remains the top scorer of the Red Devils this campaign with 14 goals in all competitions.Manchester United@ManUtd🗯 "I speak regularly to the players about how they feel and I know they realise how much they've developed and improved their performances, especially in control of the ball," adds Ralf."Now it's about taking the next step." #MUFC | #MUNSOU7:06 AM · Feb 11, 20221189109🗯 "I speak regularly to the players about how they feel and I know they realise how much they've developed and improved their performances, especially in control of the ball," adds Ralf."Now it's about taking the next step." 📈#MUFC | #MUNSOUManchester United are in a complete mess right now and have a lot to sort out in the next few months. This includes the replacement of interim manager Ralf Rangnick, who is set to take over in a two-year consultancy role at the club.We'll have to wait and see what awaits Ronaldo in the coming years if he remains at Old Trafford. But at the dusk of his career, he should get used to being substituted or find himself on the bench regardless of whoever manages the club.