If the rumour mill is to be believed, Manchester United goalkeeper David de Gea and Real Madrid defender Sergio Ramos want to swap clubs this summer.

It remains to be seen if both deals will be concluded before August's deadline, but the supposed willingness from the two players could force their respective teams into action.

With that in mind, Sports Mole has taken a look at five other players that have represented two of European football's biggest teams.

1. David Beckham

If Beckham were to be honest, he would probably admit that he would have been happy to have spent his entire career at Manchester United - a club where he won six Premier League titles, two FA Cups and the Champions League. Yet, a breakdown in his relationship with manager Sir Alex Ferguson saw him sold to Madrid for £23m in 2003.

While his stint at the Bernabeu yielded little in the way of trophies - although he did win La Liga in his final season - the England midfielder was a popular figure among the supporters. They appeared to value his workrate and eye for a pass.

2. Michael Owen

Despite scoring the odd important goal for both clubs, it would be fair to say that Owen's stints in Manchester and Madrid were relatively unremarkable. His biggest moment in a United shirt - without a doubt - was the stoppage-time winner that he scored against local rivals Manchester City at Old Trafford in 2009.

As for his spell in the white of Madrid, he lasted just the one season following his arrival from Liverpool in 2004. He found the net against the likes of Barcelona and Valencia, but with fierce competition for places at the Bernabeu, he was sold to Newcastle United just 12 months after his arrival.

3. Ruud van Nistelrooy

Few players have been a success at both clubs, but that is certainly not the case where the clinical Dutchman is concerned. In total, he scored 214 goals for these two teams. A hefty 150 came during his time with United, whom he helped to win the Premier League title, FA Cup and League Cup. On a personal level, his 25-goal haul (44 in all competitions) earned Van Nistelrooy the 2002-03 Premier League Golden Boot award.

A dispute with Ferguson resulted in him leaving for the Spanish capital in 2006 for around £8m. It was money well spent by Madrid as the striker scored 41 La Liga goals during his first two seasons, both of which ended with Los Blancos being crowned champions. However, the latter stages of his Madrid career were blighted by injuries, which resulted in the forward's departure to Hamburg in 2010.

4. Gabriel Heinze

Initially, the Argentine defender was a firm favourite among United fans following his arrival from Paris Saint-Germain in 2004, so much so that he was voted the club's Player of the Season during his debut campaign. But, having lost his place in the side to Patrice Evra during the 2006-07 season, an unhappy Heinze demanded a move to major rivals Liverpool, which soured his relationship with the supporters.

The story goes that Ferguson refused to negotiate with the Merseysiders, choosing instead to sell the left-back to Madrid. He was a part of the squad that won La Liga in 2007-08, but Heinze was never regarded as first choice before his departure for Marseille in 2009.

5. Cristiano Ronaldo

While Van Nistelrooy's combined tally of 214 goals is highly respectable, Ronaldo's 431 (and counting) is incredible. He arrived at Old Trafford from Sporting Lisbon in 2003 as a gangly teenager and left for Madrid six years later as arguably the world's best player. From his time in England, the Portuguese talisman won three Premier League titles, one FA Cup and the Champions League.

There are some that believe Madrid should have won more trophies since Ronaldo's £80m switch, but he can still boast one La Liga title, two Copa del Reys and the Champions League. On a personal level, the 30-year-old has broken a host of club and La Liga records, many of which are likely to stand for a very long time.