Gary Pallister insists that Sir Alex Ferguson is keen on bringing Real Madrid star Cristiano Ronaldo back to Manchester United in the summer, as the Red Devils look to build on their seemingly imminent record-breaking 20th Premier League title.Victory against Manchester City on Monday evening will stretch United's lead over the reigning champions to 18 points but Pallister insists that Sir Alex isn't content and plans to send out a message of intent to rivals in England and abroad.And, according to the former Red Devils defender, the Portuguese ace would be the final piece of the jigsaw as the long-standing manager plans to raise the bar.The 47-year-old told Goal.com: "I know for sure that Sir Alex would love to have Ronaldo back at Old Trafford. To be honest, I didn't think it would be likely, especially this summer, but I'm coming round to it now. A lot depends on whether Jose Mourinho stays at Real, but, if not, Ronaldo could be tempted into a return."Despite losing out to Real in the Champions League this season, United have proved they are once again the best in England and that would be important to someone like Ronaldo. Sir Alex never rests on his laurels and demands improvement every season, and Ronaldo will guarantee him not just 30 goals next season but also the league title."The only blot on this season is that Champions League exit and Sir Alex has always said that he regrets not winning the competition more often. Ronaldo was the difference between the sides over the two legs and that will not be lost on Sir Alex."Of course, if Ronaldo is available, United will have to break the bank to get him, but if it’s true that new club sponsors will be willing to underwrite the deal, then it might be an exciting summer ahead."Pallister feels United’s domestic dominance has already avenged being pipped to the title by City last season, but is certain Sir Alex has had Monday's fixture ringed in his calendar since the date was announced.He explained: "The last thing Sir Alex will tell his players before the game is to remember how it felt to lose 6-1 at home to City last season."I was at United when we lost 4-1 at home to QPR in the FA Cup, and also shipped five and six respectively at Southampton and Newcastle, but that defeat to City would probably be the most embarrassing of his managerial career."Sir Alex was determined to right those wrongs and it's no coincidence that United flew out of the traps this season and have not really looked back."What will have surprised Sir Alex is that having laid down the gauntlet, City have not really responded. Everyone expected City to kick on and be a major force, but this season has affirmed without much of a fuss that United once again hold the balance of power in Manchester."