With the departure of club captain Jack Cork, a gaping hole has been left in Swansea City's starting lineup. The 28-year old had been a solid and consistent presence, doing the unheralded dirty work that allowed others to flourish around him.
With Cork leaving, the a spot in central midfield spot has been vacated. However, there are at least four candidates to occupy the berth, alongside new signing, Roque Mesa. These are: Leon Britton, Tom Carroll, Leroy Fer, and Ki Sung-yueng.
With Britton's advancing years, the club legend is likely to be best served playing a more limited role off the bench, thus leaving the younger three, all battling it out to be first choice at the start of the season. But who's claims to start is the strongest?
If the Swans want continuity, Carroll is the guy. Like Cork, he provides a steady, metronomic presence in the centre of the park.
Above all, Carroll is a solid passer, and last season was particularly active in the final third. The Englishman averaged 0.76 key passes last season - more than either Ki (0.52), or Fer (0.47).
With his passing comes goalscoring opportunities. He created 0.88 chances per game in 2016/178 - mpre than either Ki or Fer, who averaged 0.57, and 0.53 respectively.
The 25-year old is a sturdy defensive presence, which would nicely complement Roque Mesa's more stylish play. Willing to get stuck in with challenges, Carroll has a good-eye for breaking up opposition attacks, averaging 1.06 interceptions during his first permanent year with the Swans. His discipline was also key. Throughout the 2016-2017 campaign, he was only booked once.
However, Carroll does have his weaknesses. He is not a particularly potent offensive force, scoring just one goal last season. The former Spurs player also lacks the creativity of either Ki, or Fer.
More glaringly, he struggles in the air, a vital role for any defensive midfielder. Carroll won only 37.5% of aerial duels last season, not helped by his lack of size.
Leroy Fer is the most dangerous goalscoring threat of the three. He can use his large frame to dominate in the air, whilst his striking power saw him register six league goals last season.
The Dutch midfielder is a powerful athlete, and sometimes uses these tools on defence. Unafraid of throwing himself into the fray, Fer averaged 3.59 tackles per game in 2016/2017 - even if his 33% success rate leaves a lot to be desired.
Fer's aerial dominance particularly stands out. He won a tremendous 65.22% of his aerial duels last season.
However, like Carroll, he has his flaws. Outside of physicality and effort, he is a poor defender. Furthermore, when not involved in the final product, he contributes little offensively.
A Fer/Mesa combination would arguably also lack the defence needed against some of the Premier League's stronger offences.
If at the top of his game, Ki Sung-yueng would be a shoe-in for the spot.
Ki was previously one of Swansea's best players, with his dynamic passing and offensive flair contributing greatly to the Swans. In 2014/2015, he scored eight goals.
His vaunted passing remains his biggest strength, with Ki continuing to average a passing accuracy of around 90% every season. At his best, the South Korean makes everyone on the team better with his effective passing.
The 28-year old is also a skilled shooter, able to score from distance, or in-close. He includes in his repertoire a deadly free-kick, which he showed whilst at Celtic. However, at Swansea he has largely been consigned to the passing-creator role.
That said, the last few years have been difficult for Ki. The last two seasons have seen the midfielder plagued by injury, and poor form. At times he can appear sluggish, and is certainly not at the level he was back in 2014/2015.
Unlike both Carroll and Fer, Ki is neither a skilled, nor willing tackler. He also struggles in the air despite his good size, winning only 41.67% of his aerial duels - although has shown himself capable in the past.
His fit with Mesa is also questionable. Both are excellent passers and creators, but lack the presence to compete defensively.
Taking everything into account, the best choice would be to start Ki Sung-yueng.
Ki's combination of creativity, passing, and technical skill makes him the best option when factoring in two-way play. He is less of a defensive liability than Fer, whilst he provides more offence, and aerial power than Tom Carroll.
Both Carroll and Fer will have major roles to play for Swansea going forward. Whilst Ki recovers from injury and prepares for the new season, they can each fill in the gaps.
Caroll offers a reliable presence, whilst Fer can help inject some physical dominance, something the Swans can sometimes lack on both ends.