Manchester United have hit their stride at just the right time, and after five straight Premier League wins have a place in the Champions League close to sewn up. But while the primary objective is now close to being reached, there is little doubt that the club will want to see further strides made in Louis van Gaal’s second season in charge. And toward that aim, there is likely to be considerable spending in this summer’s transfer window.

Securing a top class center-back is set to be a priority, and the man long thought to be their leading target is continuing to suggest that he could now be ready to make a move. Having previously insisted upon his committed to Borussia Dortmund, Mats Hummels’ tone has notably wavered in recent weeks on the back of his club’s hugely disappointing season. Having last week suggested that he would wait to see whether Dortmund significantly improved their squad before deciding on his future, he reiterated that he was weighing up his options after Dortmund’s 1-0 defeat to Bayern Munich on Saturday.

“That doesn’t mean that I am leaving, it just means I’m reflecting,” he told Sky television. “There’s no particular tendency one way or the other. It’s just thoughts going through my mind. It will all become clearer in the coming weeks.”

There are reports that United are willing to pay 40 million euros (£29.2 million) for the 26-year-old who helped Germany to lift the World Cup last summer. Were United to finally secure the services of Hummels, it would likely mean an end their interest in Valencia center-back Nicolas Otamendi. The Argentinian has played a big part in Valencia’s challenge for a Champions League place and was strongly linked with a transfer to Old Trafford in January. Sky Sports’ Spanish soccer expert Graham Hunter believes United’s interest will resurface come the end of the season.

“Manchester United's interest in acquiring Otamendi is well established,” he said. “Therefore, I would expect them to try to buy him in the summer. If they come in with £50 million then Valencia have a decision to make.”

It would be a major surprise, however, were United to go anywhere near that £50 million figure for a 27-year-old, particularly if Hummels arrives. And, if Valencia hang onto a Champions League place, they would have little motivation to sell.

As well as a center-back, a new right-back looks sure to be on the transfer agenda. Van Gaal has clearly not taken to Rafael da Silva, while Antonio Valencia remains very much a midfielder playing out of position at full-back. Speculation continues to suggest that Southampton’s Nathaniel Clyne is the player wanted by Van Gaal to fill the position next season.

Clyne rejected the chance to move to Old Trafford when he left Crystal Palace for Southampton in 2012, as he sought a club where he would get regular playing time. But his performances since in the Premier League, which have earned him four England caps, suggest he is now ready for the step up. Yet, while Clyne has turned down an extension to a contract that expires in 2016, Southampton have not yet given up hope of losing him this summer, according to the Daily Mirror. With United, along with Chelsea and Liverpool, thought to be interested, though, they may well be fighting a losing battle.

Meanwhile, it is hard not to envisage their being a significant overhaul of Manchester United’s forward options this summer. Van Gaal appears to have long since decided against signing Radamel Falcao on a permanent basis, and Robin van Persie has scored just 10 goals all season amid continued concerns over his form and fitness.

The Daily Mirror has now reported that Van Gaal is prepared to see his fellow Dutchman to depart, and has lined up Paris Saint-Germain’s Edinson Cavani as a replacement. Cavani has voiced his frustration at consistently been asked to play out wide since being signed from Napoli for around £55 million in 2013, and he had a heated confrontation with manager Laurent Blanc when being substituted against Marseille on Sunday. Now the 28-year-old’s agent has suggested his client could well be on the move, with England or Spain the most probable destinations.

“Right now it seems early to say whether he will be on the market,” Claudio Anelluci told Radio Olympia, reports Gazzetta dello Sport. “Edy is under contract with PSG, and several factors come into play. Once the situation is clarifies, many different scenarios are possible, given that players like him, at the peak of their careers, are coveted by Europe's top clubs. The markets in Spain and England currently look the most likely.”