Former Premier League striker Noel Whelan believes Manchester United forward Marcus Rashford may have huge behind-the-scenes issues at the club.The 24-year-old has encountered a problematic period at United this season, having dropped out of the starting XI following a poor run of form.According to Fabrizio Romano, Rashford is considering his future due to the lack of game time he has been afforded under interim manager Ralf Rangnick.With Cristiano Ronaldo and Edinson Cavani ruled out of the Red Devils' clash with Leicester City last Saturday, many had envisioned the forward to start up front for the side.But he was left on the substitutes' bench with Bruno Fernandes given a false nine role. His omission has been a regular occurrence this season for Rashford.Whelan has commented on the striker's demeanor, telling Football Insider that he didn't warrant being selected for the Leicester game:“He hasn’t done enough to warrant a start."Whelan continued,“In fact, he hasn’t done anything of note at Man United for a long time. I don’t know what’s happened this season. Whether he’s lost that desire, that passion, the hard graft – I don’t know. He doesn’t look excited out there anymore."Having been heralded by many as Manchester United's finest academy product in years, and having taken to life in the senior set-up in great fashion, his huge drop in form has been alarming.Whelan commented further in this regard, saying:“That’s a big problem. We want to see him with that energy, that pace, the skill and the directness. But whether it’s a behind the scenes problem, I don’t know – but he looks uninterested at the moment. He used to play with a smile on his face, but we don’t see much of that anymore.”Sky Sports Premier League@SkySportsPL🗣 "I think his time has run now at Man Utd." Jamie Redknapp believes that Marcus Rashford needs to leave #MUFC to rediscover his love for the game 1:05 PM · Apr 4, 20221148101🗣 "I think his time has run now at Man Utd." Jamie Redknapp believes that Marcus Rashford needs to leave #MUFC to rediscover his love for the game 🔴💬 https://t.co/OAJtCmDCx1Concerning times for Marcus Rashford at Manchester UnitedIt has been a season to forget for the Manchester United forwardThe first sign that all was not okay for the forward was the player's attitude in Manchester United's FA Cup fourth-round encounter with Aston Villa.Rashford got a huge opportunity to score in the crucial game but provided a tame shot.Following the game, Premier League legend Alan Shearer commented on Rashford's poor showing this season, stating that something was wrong with the forward.He told BBC Sport:"A lot of the times this season it looks like everything is a chore, a lot of it looks like hard work for him and he doesn't seem to be enjoying his football as much."Fabrizio Romano@FabrizioRomanoParis Saint-Germain had Marcus Rashford name in their list as option [not the only one] to replace Kylian Mbappé last summer in case of deal agreed with Real Madrid. 🏴󠁧󠁢󠁥󠁮󠁧󠁿 #PSGNo new/fresh contacts with PSG as of now - Rashford is considering his future and it will take time.10:29 PM · Mar 7, 2022266191946Paris Saint-Germain had Marcus Rashford name in their list as option [not the only one] to replace Kylian Mbappé last summer in case of deal agreed with Real Madrid. 🇫🇷🏴󠁧󠁢󠁥󠁮󠁧󠁿 #PSGNo new/fresh contacts with PSG as of now - Rashford is considering his future and it will take time.It remains to be seen what the future holds for Rashford at Old Trafford.He has been linked with Arsenal, PSG and West Ham United.But with Ajax's Erik ten Hag on the verge of becoming the club's next manager, perhaps he will be able to turn the forward's misfortunes around.