The latest transfer saga of the summer looks set to run for a while longer yet. Manchester United are thought to be in a three-way tussle with Real Madrid and Chelsea for the signature of Tottenham midfielder Luka Modric.

Guillem Balague reports in Spanish publication AS that Real's move for the Croatian has hit a major hitch with midfielder Nuri Sahin unwilling to move to Spurs in part exchange. Unsurprisingly it seems that Tottenham are not enamored with the idea of letting their star man leave for a Premier League rival.

Though an offer from Real Madrid is sure to prove a huge lure for Modric, the playmaker is thought to be tempted by the chance of more regular first-team action at Old Trafford. However, Tottenham's reported €50 million (£40m) asking price is likely to prove a significant stumbling block to any deal.

If Tottenham lose Modric, it is widely believed that they will attempt to bring in Portugal's Joao Moutinho as a replacement. This particular transfer merry-go-round has taken another twist with various sources, including the Daily Mail, reporting that United also see the Porto star as an alternative to Modric.

Moutinho, 25, was one of Portugal's standout performers as they reached the semifinals at Euro 2012. Portuguese publication O Jogo reports that United have offered £25 million for Moutinho, though the Mail reports Porto value him at £32 million. That valuation looks unlikely to be met by either Spurs or United, though Manchester City and Chelsea are also said to be interested.

There has been further speculation of late about United's reported pursuit of Everton left-back Leighton Baines. The Mirror claims that United are to up their offer for the England international this week to £12 million. According to the story, Everton may be prepared to accept the bid in order that manager David Moyes can have some finds to strengthen his squad.

Baines has said that he is still none the wiser about any deal.

I'm aware of what's been said about United, but I don't know much beyond that, Baines said.

It can be a problem for ­Everton given the financial situation at the club.

Over the years the manager has lost players I am sure he would have liked to have kept hold of.

Maybe the club has needed the money or maybe they have received a substantial bid for a player.

After having already secured the signing of Shinji Kagawa, speculation has suggested that United may be prepared to return to raid Borussia Dortmund of their star center-back Mats Hummels.

The 23 year old has played a key role in Dortmund's back-to-back Bundesliga titles in the past two seasons and is thought to be highly coveted across Europe. Hummels, however, has said that he is happy to remain at the Westfalenstadion.

I recently renewed with Borussia and signed a long-term contract, he said, according to Manchester United's website. Honestly, I do not lose sleep right now over the rumors about me.

Mats' father, Hermann has also claimed that his son is not interested in joining United.

Of course, those comments may be immaterial if Sir Alex Ferguson witnessed the way in which Antonio Cassano turned Hummels like he wasn't there to set-up Italy's opening goal of their Euro 2012 semifinal with Germany.