Manchester United still have one outstanding sum of £6.7 million to pay to PSV Eindhoven at the end of the season as part of their agreement for under-performing summer signing Memphis Depay. 

The details of his transfer have been revealed by Football Leaks (h/t Jonny Boyle of talkingbaws.com), with United having already paid £13.35 million up front to the Eredivisie side and £6.7 million midway through the campaign, and the Red Devils are due to make the same payment again this summer.

United would also have to pay over £1 million for winning the Premier League and another £1 million for UEFA Champions League success.

Depay arrived at Old Trafford with an impressive reputation after racking up 28 goals and eight assists for PSV last year, but he has struggled to make a significant impact this season.

The 22-year-old has scored seven goals and assisted six in all competitions for the Red Devils—hardly inspiring tallies but not awful by any means—but just two and one, respectively, have come in the Premier League.

Indeed, his season has largely been characterised by a number of ineffective and frustrating performances.

The Manchester Evening News' Samuel Luckhurst compared the forward to former United player Kieran Richardson, who failed to make the grade at Old Trafford:

Another 2005-06 parallel: Memphis is resembling Kieran Richardson #mufc https://t.co/Yi2Nou5hEP

— Samuel Luckhurst (@samuelluckhurst) January 4, 2016

As noted by Rob Dawson of the same source, Red Devils fans' patience with him has also worn thin at times:

Memphis shoots wide from outside the box. United fans ironically clap and cheer like he's scored. Making their feelings known. Still 0-0.

— Rob Dawson (@RobDawsonMEN) January 9, 2016

What will give the Old Trafford faithful some encouragement is his slow but steady improvement in recent weeks.

The Dutchman played a starring role as United beat FC Midtjylland 5-1 in the UEFA Europa League, scoring and assisting one apiece and showing some delightful moves, per BT Sport Football:

Outrageous nutmeg from @Memphis 🔥#UEL #MUFC https://t.co/0njX5tqFhT

— BT Sport Football (@btsportfootball) February 25, 2016

Football writer Liam Canning hailed his turnaround in form:

Huge props to Memphis. Been under an onslaught of criticism this season and now starting to turn it around. Last two games been magnificent.

— Liam (@OffsideLiam) February 28, 2016

That’s 3 games in a row that Memphis has been a star performer. Slowly but surely he’s regaining his confidence. Brilliant to see.

— Liam (@OffsideLiam) March 2, 2016

So too has Bleacher Report's own Sam Tighe:

Positive signs for #MUFC as Memphis Depay shows glimpses of growing tactical maturity under LVG | @stighefootballhttps://t.co/8g7ji1NerN

— Bleacher Report UK (@br_uk) March 2, 2016

The forward continued his good form into the international break, providing two assists for the Netherlands on Friday against France.

He's not come close to justifying the amount United have paid for him, but if he can continue to settle at United and regain his confidence, he may become the player they were hoping for.

Over time he could well end up warranting his price tag, but it's clear he still has a long way to go—starting with a strong end to the season.