As the Premier League season draws to a close, there are several gems of free agents yet to renew their contracts for next season.

Huddersfield Town are embroiled in a fight to preserve their top-flight status but David Wagner will already have begun planning for the future in earnest.

With the Terriers lacking backup in the centre of defence and midfield, a clutch of proven performers will become available at the end of the season - without needing to pay a penny.

Here, sports writer Tom Harle takes a look at a selection.

1. Ki Sung-yueng

The Korean schemer has already said he's uncertain of his future at Swansea, with contract talks yet to take place, so could well leave the club.

The 29-year-old is superb technically and has an excellent passing range, despite being asked to play a more pragmatic role as the South Wales side fight for survival.

Crucial goals against Burnley and West Ham put Ki in the spotlight, leading to him being linked with Italian giants AC Milan in March.

2. Scott Arfield

Scott Arfield in action for Burnley against Town in their December goalless draw

The erstwhile wideman hasn't been quite such a key member of Sean Dyche's side this season, but remains a proven performer at the highest level.

He made 31 starts on the Clarets' return to the top flight and his end product is consistently of high quality, as well as being an asset for his ability to play on either flank.

Arfield was offered a new contract in January amid interest from West Ham and is yet to commit his future to the Turf Moor outfit.

3. Joel Ward

Ward has been frustrated by a lack of first-team football with the Eagles in recent weeks and Roy Hodgson's preference for youngster Aaron Wan-Bissaka is likely to be the final nail in the coffin.

The versatile 28-year-old still has plenty to add in the Premier League and was an ever-present at Selhurst Park just last season.

Able to play in either full-back role, in the heart of defence or even the middle of midfield, Ward would be an asset to any hard-pressed Premier League manager.

4. Claudio Yacob

The Argentine terrier would add bite to any Premier League midfield and has remained a firm favourite at the Hawthorns despite their struggles this season.

Strong speculation has linked the 30-year-old with a move back to his home country after six seasons in the top flight there kicked off his career.

A destroyer in the Danny Williams mould, Yacob lacks the American's mobility but consistently ranks highly in successful tackles made and interceptions.

Midfield harrier Yacob is available as a free agent this summer when his contract runs out

5. James Collins

Wagner is not blessed with backup in the centre-half positions, although it's not been an urgent issue for the German given the form and fitness of Christopher Schindler and Zanka at the heart of defence.

Injuries to Michael Hefele and Terence Kongolo in the second half of the season have left him short and Collins is exactly the kind of grizzled, proven top-flight performer he may look to.

The Hammers have not tabled a new deal for the Welshman who has admitted it will be a wrench to leave East London, with another Premier League side sure to benefit from his leadership qualities and physical attributes.

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6. Robert Huth

Deeply out of favour at Leicester City, the German powerhouse has only appeared in early rounds of the FA Cup and the Checkatrade Trophy this term.

The central defender is settled in Cheshire and is likely to court interest in this country.

What he lacks in pace, the 33-year-old makes up for in aerial presence in both boxes as well as adding an experienced head to the dressing-room.