With the summer transfer window fast approaching, many top teams around Europe will be looking to bolster their squads, spending absurd amounts of money in the process.

Last summer, Premier League clubs spent £2.36 billion on players – a new record for transfer spending – and it’s unlikely this trend of increased year-on-year expenditure will stop come June.

International tournaments are also notorious for inflating players’ transfer fees if they impress, meaning this summer’s Euros in Germany will almost certainly result in clubs shelling out huge sums of cash to acquire talent.

However, these clubs would be foolish to overlook the impressive array of players who can be snapped up for free when their contracts run out in just a few months. With Financial Fair Play regulations and hangover from the Covid-19 pandemic having a huge influence on how much teams can spend, club owners would be wise to turn their attention towards signing players at zero cost.

As such, Mail Sport has put together a Free Agents XI of the best players on the market this summer who are out of contract, lining up in a 4-3-3 formation.

Goalkeeper – Koen Casteels

A product of the famous Genk youth academy that has produced the likes of Kevin De Bruyne and Thibaut Courtois, Casteels has spent all of his professional career in Germany.

However, this could change in the summer when the Belgium international’s time at Wolfsburg comes to an end following a nine-year spell.

Having made 233 appearances for Die Wolfe and represented his country on eight occasions, a move for Casteels would represent a savvy piece of business for sides looking to add a tried and tested keeper to their ranks.

Nottingham Forest reportedly made a move for the goalie in January, making the Premier League a likely destination for him next season.

Defender – Ben Johnson

The West Ham star has yet to put pen to paper on a new deal, having seen his minutes deplete under David Moyes this season.

Johnson’s versatility has almost been a vice for him during his days with the Hammers, adept at playing across the back four but seemingly never trusted to operate one role in the starting XI consistently.

It appears the English defender is ready to start a new chapter and could be on the way out of West Ham for nothing this summer. Leeds United are understood to be interested in a move for Johnson, although their ambition will rest heavily on their success in the Championship playoffs.

At 24, Johnson still has plenty of mileage left in him and could be a fruitful pick-up on a free transfer at the end of the season.

Defender – Raphael Varane

Those familiar with Spanish and English football will need no introduction to the France international, who has picked up a remarkable 21 trophies throughout his career, including four Champions Leagues and a World Cup.

Varane is widely regarded as one of the outstanding players of his generation and is undoubtedly an icon of Real Madrid, the club who boast the game’s most illustrious list of current and former players.

Despite his achievements for France and Los Blancos, Varane has had a turbulent time in England since arriving at Old Trafford in 2021.

The defender has been in and out of the starting lineup under Erik ten Hag and has seemingly struggled to adapt to the English game in the way United fans would have hoped.

However, at 31 years of age, Varane is still a player who could make an impact at a whole host of top European clubs.

If United do decide to part ways with the coveted centre back, he won’t be short of managers and coaches looking to get him on the books.

Defender – Tosin Adarabioyo

Since leaving Manchester City in 2020, Tosin has enjoyed a successful couple of seasons at Fulham under Marco Silva.

Although the 26-year-old defender is yet to receive his first England call-up, he could be an outside choice for inclusion in this year’s Euros squad given the Three Lions’ frailty in defensive positions.

He predominantly plays at centre back for Fulham, but has featured at right back on occasion.

With his contract expiring soon, the Fulham man has been linked with a whole host of Premier League clubs, with Newcastle United his most likely destination at this stage.

However, Liverpool, Spurs and West Ham have all reportedly shown interest in signing him.

Whoever acquires his services will have secured a fantastic piece of business given his age, height and ability on the ball.

Defender – Mario Hermoso

Although Atletico Madrid spent almost £25m on Hermoso in 2019, it seems the Spaniard could be on the move once again, this time for no cost at all.

At 28 years of age, arguably the prime of a defender’s career, Hermoso would be an interesting prospect for any top European club – especially when you consider his experience playing in elite European competitions.

Aston Villa and Inter Milan are currently in the race of the Spain international’s signature, with both teams likely to be playing in the Champions League next season.

Hermoso’s versatility is also an attractive quality, with the former Espanyol and Real Madrid player able to play either the left back or centre back.

Midfield – Thiago

Despite arriving on Merseyside to great acclaim after a Champions League winning campaign at Bayern Munich, the Spain international has struggled to find form and fitness over the past two seasons.

He has managed just five minutes in the Premier League this season, coming on in Liverpool’s 3-1 defeat to Arsenal in February.

Although injuries have plagued Thiago’s career, his trophy haul alone should be enough to attract interest from top sides, whether in England or on the continent.

When fit, he is still able to impress with his exceptional dribbling technique and vision.

Midfield – Toni Kroos

Even though the Germany and Real Madrid midfielder is now entering the twilight of his highly successful career, he is still able to churn out performances reminiscent of his prime.

He has managed a goal and eight assists in all competitions for his club side this season, demonstrating that his career is not finished at the top level.

While Kroos looks set to sign a one year extension at Real Madrid, especially now that Ancelotti will stay in the Spanish capital until 2026, nothing has been formalised at this stage.

Although his age and contract demands may be an issue for teams, no one can deny the German brings quality and experience to any side he plays in.

Midfield – Adrien Rabiot

Once touted with joining Manchester United, the Juventus midfielder has represented France on 43 occasions, scoring four times.

This season, Rabiot has made 29 Serie A appearances for the Old Lady and managed seven goal contributions.

Given the calibre of teams the 29-year-old has represented throughout his career, he would be an interesting option for a team like the Red Devils, who require greater depth and quality in midfield.

Forward – Anthony Martial

With reports indicating Manchester United will not be extending Martial’s contract in the summer, the Premier League club will be calling time on the tenure of a player who greatly underachieved in England.

Since returning from his loan spell at Spanish side Sevilla, the forward has contributed just one goal in 13 Premier League games this season.

Although his time at Manchester United was largely unsuccessful, Martial has still managed to score 63 goals in 209 games for the English club.

He will still surely attract interest from sides around Europe, though it’s unlikely a Premier League team will take a risk on him given his recent lack of success.

Forward – Luka Jovic

Despite a highly anticipated move to Real Madrid in 2019, Jovic failed to live up to the dizzying heights expected of him.

Now at Italian giants AC Milan, the striker has managed nine goals and an assist in 29 games this season.

With his contract up at the end of the season, Milan have the option to extend his contract for a further year.

However, nothing has been agreed yet and the Serbian international may well be on the move once again.

Forward – Kylian Mbappe

Although it appears Mbappe’s transfer to Real Madrid is all but finalised, nothing has been formally announced at this stage except for the France player’s departure from PSG.

Arsenal, Liverpool and Manchester City have all been linked with his signature in recent seasons, and the World Cup winner’s pace and finishing ability would benefit any top Premier League side.

Mbappe’s move will undoubtedly be the transfer news of the summer and his statistics this season show why.

The versatile forward is joint top Champions League scorer alongside Kane and won the Ligue 1 golden boot by some margin, racking up 26 goals in 28 games.