Casemiro represented Real Madrid between 2013 and 2022, making 336 appearances for the Spanish giants, winning three La Liga titles, one Copa del Rey and five Champions League trophies in the process.
Man United purchased the Brazilian in the summer of 2022, and he was in outstanding form for the Red Devils during the 2022-23 campaign, scoring seven times in 51 appearances in all competitions.
The 32-year-old found it difficult to make his mark during the 2023-24 season, though, being restricted to just 32 appearances, and he was heavily linked with a move away from Old Trafford over the summer.
There is believed to have been Saudi Arabian interest in Casemiro, but he remained at Old Trafford, and the midfielder has made 16 appearances for the English giants this term, scoring three times in the process.
Real Madrid 'considering making attempt to re-sign Casemiro'
Casemiro has started Man United's last four Premier League matches, and he has a contract with the 20-time English champions until June 2026, with the option of a further 12 months.
There are question marks over his suitability for Ruben Amorim's 3-4-3 system, though, with the new Man United head coach expected to select Manuel Ugarte and Kobbie Mainoo as the central two in that formation.
According to Trivela, Real Madrid chiefs are currently discussing Casemiro, with Los Blancos open to the idea of bringing him back to Bernabeu due to their injury problems.
Aurelien Tchouameni is in the latter stages of his recovery from an ankle problem, but it is likely that he will be required in central defence for the remainder of the season due to Eder Militao's season-ending knee injury.
David Alaba is due to return in January, but it will be some time before the Austrian, who has been out for almost a year, is back to full fitness, which could lead to Tchouameni operating alongside Antonio Rudiger in the middle of the defence.
Does a Real Madrid move for Casemiro make sense?
Real Madrid are a Rudiger injury away from a serious crisis at the back, and it would therefore not be a surprise to see the club bolster their options in that area of the field during the January transfer window.
Los Blancos will not shell out a big fee in the winter, though, which could lead to them looking for a short-term option, and Casemiro is capable of filling in at the back.
The Brazilian found it difficult during his spell in the middle of the defence for Man United last season, but he could play in that area in a league which does not have the same tempo as England's top flight.
As a result, a return to Bernabeu is not completely unrealistic, especially with Man United seemingly keen to move him on due to his immense wages, which are believed to be in the region of £300,000 a week.
A return to Real Madrid on a short-term deal could be appealing, with Casemiro then potentially making the move to the Saudi Arabia next summer to close out his career, while Los Blancos are said to believe that he could play an important role in the development of both Tchouameni and Eduardo Camavinga.
Will Casemiro be involved for Man United at Ipswich?
Casemiro is out of the picture when it comes to the Brazil squad, so he has had a break over the last couple of weeks, travelling to the United States for a holiday, which has been criticised by ex-Red Devils captain Gary Neville.
"The professionalism, looking after your body and making sure you're best prepared for the next training session is critical to every decision you make during the season," Neville said on the Stick to Football podcast, with Marcus Rashford also heading to the United States after not being picked by England.
"He [Marcus Rashford] has got a mental break, he's got to get away and has got to rest with friends - then you talk about the choice of venue, how far do you fly, what's the time difference, is that going to give a jet lag issue, is that going to give a stiffness issue from being on a flight for 12 hours?
"This is on Casemiro more than Rashford but if I'm 30 years old and I'm looking after my body - and he's won five Champions Leagues and is an unbelievable player, but if he was away with Brazil for 10 days, we would say he would struggle this weekend because he's been away.
"They [Casemiro and Marcus Rashford] have chosen that international break. If you are talking about the minor details in being as professional as you can be and as prepared you can be for a training session [the next day] on a Monday night, that isn't the best choice of venue.
"I'm not that wound up about [Marcus] Rashford and Casemiro going over to the United States but what I'm asking is, if you've got a four-day break, Portland is a 12-hour flight and an eight-hour time difference, your jetlag is bad, and you feel a bit [rough].
"They went to Portland and I'm asking the question based on professionalism - you're playing badly, the team are losing, you're 13th in the league, and there is a new manager coming in - would you choose that trip as a break to recharge your batteries? That's not a recharging trip. It's not right, that."
Casemiro has been training under Amorim this week, though, and the experienced midfielder is in line to be a part of the squad that heads to Portman Road for Sunday's Premier League clash with Ipswich Town.