Toby Alderweireld has bee hugely missed during Southampton's recent run which has seen them drop to fifth in the Premier League after some uncharacteristic performances.
The Belgian has not featured since limping off in the first 20 minutes of the 1-0 win at Old Trafford and his side have not been the same since.
Without him in the side the Saints seem slightly on edge and lacking in composure, something which the on-loan star brings in abundance.
Prior to his injury, Alderweireld was a contender for the Southampton player of the season so far such was his impressive start to life in England.
A string of confident, relaxed performances saw the Saints defence become the tightest in England's top four divisions.
That has made his absence all the more costly as the Southampton back line has not quite looked the same when he is not in the team.
The 6ft 1in defender has brought an extra element of class to the Southampton side thanks to his Champions League experiences.
He has shown his ability on the ball by comfortably stepping into a central midfield role when required.
His recent performances have not gone unnoticed though with Manchester City rumoured to be showing an interest in him ahead of the summer.
Maya Yoshida is currently deputising for the 25-year-old and although he does not look out of place in the Southampton team, Alderweireld is still missed.
The Japanese star has formed a solid partnership with Jose Fonte, however when the Southampton captain is alongside the Atletico Madrid star the Saints look a more formidable opponent to break down.
Southampton fans will be hopeful that their loan star will soon be fit to return to action after a recent shaky period.
With the quality on the ball he possesses combined with his ability to read the game, Koeman will also be happy to have the Belgian international available for selection.
Should he return soon the Saints can still push for a fourth placed finish this season, knowing that if they don't, it will be even harder to keep their man at St. Mary's for the next campaign.