ESPN pundit Shaka Hislop has advised Manchester United striker Cristiano Ronaldo to return to Portugal and play one more season before retiring.The former West Ham United goalkeeper was answering questions from fans on Twitter when he was asked if Ronaldo should retire after the current season.He responded:"Go back to Portugal and play one more season."It comes following yet more uncertainty over his future at Manchester United has taken hold.Reports claim that United boss Erik ten Hag is now open to offloading the Portuguese forward in the January transfer window.The Dutch tactician left Ronaldo on the bench for the entirety of the Red Devils' disappointing 6-3 defeat to cross-city rivals Manchester City on October 2.He explained his decision after the loss saying (via Sky Sports):"I didn't bring him on out of respect for his big career."Cristiano Ronaldo has made a poor start to the season.He has made eight appearances in all competitions, scoring just one penalty against Sheriff Tiraspol in the UEFA Europa League.United's handling of the Portuguese has received backlash from many, including legendary midfielder Roy Keane.The Irishman finds the Red Devils' treatment of the legendary forward as disrespectful.Sky Sports Premier League@SkySportsPL"𝙈𝙖𝙣𝙘𝙝𝙚𝙨𝙩𝙚𝙧 𝙐𝙣𝙞𝙩𝙚𝙙 𝙝𝙖𝙫𝙚 𝙨𝙝𝙤𝙬𝙣 𝙣𝙤𝙩𝙝𝙞𝙣𝙜 𝙗𝙪𝙩 𝙙𝙞𝙨𝙧𝙚𝙨𝙥𝙚𝙘𝙩 𝙩𝙤 𝙍𝙤𝙣𝙖𝙡𝙙𝙤!" Roy Keane believes Man United should have let Cristiano Ronaldo leave the club in the summer.232193061"𝙈𝙖𝙣𝙘𝙝𝙚𝙨𝙩𝙚𝙧 𝙐𝙣𝙞𝙩𝙚𝙙 𝙝𝙖𝙫𝙚 𝙨𝙝𝙤𝙬𝙣 𝙣𝙤𝙩𝙝𝙞𝙣𝙜 𝙗𝙪𝙩 𝙙𝙞𝙨𝙧𝙚𝙨𝙥𝙚𝙘𝙩 𝙩𝙤 𝙍𝙤𝙣𝙖𝙡𝙙𝙤!" 😤Roy Keane believes Man United should have let Cristiano Ronaldo leave the club in the summer. https://t.co/Zgs4vlItPGRonaldo rejoined Manchester United from Juventus in 2021 for £13.5 million.He has made 46 appearances during his second spell at Old Trafford, scoring 29 goals.The former Real Madrid striker finished the club's top goalscorer last season but is now playing a bit-part role under Ten Hag.Manchester United's Cristiano Ronaldo could return to Sporting CPRonaldo began his career at Sporting CPA Primera Liga side that were touted as potential suitors for Cristiano Ronaldo throughout the summer were his former side Sporting CP.The Lisbon side were reportedly active behind-the-scenes in the latter stages of the summer transfer window in trying to find a deal for the forward.A return to Sporting for Ronaldo has been something his mother Dolores Aveiro has seemingly something she has always desired.She has said with regards to the potential reunion:“It could happen, but not now. It wasn’t this year, it could happen next year. This year or next year he appears, God willing."Football Tweet ⚽@Football__TweetRun it back to 2003. Pre-season. Sporting Lisbon vs. Manchester United. The day Cristiano Ronaldo introduced himself to the Premier League's most dominant team and the game that convinced Sir Alex Ferguson to sign the tricky Portuguese winger before he left the stadium. 1015102Run it back to 2003. Pre-season. Sporting Lisbon vs. Manchester United. The day Cristiano Ronaldo introduced himself to the Premier League's most dominant team and the game that convinced Sir Alex Ferguson to sign the tricky Portuguese winger before he left the stadium. 🔥🇵🇹 https://t.co/2oMJfepKrdCristiano Ronaldo began his meteoric rise to football stardom at the José Alvalade Stadium, managing 31 appearances, scoring five goals and contributing six assists.It was in a pre-season friendly in 2003 between Sporting and Manchester United that a decision was made by the Red Devils to lure him to Old Trafford for £17.1 million.He has gone on to win three Premier League titles during his career as well as five Champions League trophies, among other honors.