Mauricio Pellegrino's fears have become a reality as his front man, Shane Long, has picked up a rather devastating injury while off on international duty for the Republic of Ireland, although it's not quite known what the extent of his absence may be.
The Southampton attacker has struggled to hit the ground running this season under the new boss despite starting each of the Saint's last three Premier League outings. Most recently, the former Hull City and West Bromwich Albion striker racked up his first full ninety minutes of football this campaign in the club's defeat to Stoke City last weekend.
Long, more or less the focal point of his nation's front line, was hoping to help lead the Republic of Ireland to a spot at next summer's World Cup, but him and his team-mates will have to overcome to stern Wales team in Cardiff and grab all three points.
The 30 year-old has had to settle for a rotational role under Pellegrino this term, with the manager originally preferring Italian Manolo Gabbiadini as the lone forward in this underperforming Southampton side, however, the Argentine has opted for Shane Long in recent weeks.
Is Shane Long's hip injury a major blow for Southampton?
As previously mentioned, the damage of the actual injury is yet to be discovered but supporters are grasping for the worst and he may miss a number of weeks of the domestic season with this infuriating spell on the side lines.
From an international perspective, Long's absence from the Republic of Ireland's final World Cup qualifier will have been of a significant blow as he would have hoped to write his name in a large part of the country's footballing history - it could potentially be their first tournament on the global stage since the 2002 competition, which was held in South Korea.
Shane Long's record at club level has been far from impressive, especially since his brief purple patch halfway through the 2016/17 campaign.
The Saints player hasn't found the back of the net on a competitive basis since February, going an accumulation of 24 games for Southampton and Ireland without being able to find himself a goal - so it can be bewildering to some as to why Mauricio Pellegrino has preferred him over Gabbadini in the last month or so.
For all we know, Long could very well be back for the club's next league fixture against Newcastle United this Sunday but in the scenario that he isn't then his unavailability for team selection won't be a major issue for Pellegrino.
Is the striker's future at Southampton in jeopardy?
The Saints' appalling start to the Premier League season has seen Mauricio Pellegrino receive mild criticism, predominantly for being reluctant to change the system and shape of the team, with the capability of finding a goal being a massive problem for Southampton up to this point.
In a desperate attempt to rediscover the fire power up front, the boss did switch to Shane Long for the away triumph over Crystal Palace last month but the Republic of Ireland international has failed to repay the manager's faith.
Back in the summer window, there were minor rumours suggesting Long could make a highly anticipated return to his original employer, Reading of the Championship, but a move never materialised and remains a Southampton player until the winter transfer window at the very least.
His struggle to bag a goal on a consistent basis over the previous eight months may just prove he is dipping towards the end of his career and the Saints could do with shipping him out in January, either on loan or permanently, as the club will aim to rejuvenate a diminishing season if things haven't changed for the better come Christmas time.