Louis van Gaal looks to have made a huge mistake signing Marcos Rojo this summer. Based on his first two appearances he doesn't look anywhere near the £16 million player that Manchester United paid for.
The Argentina international wasn't exactly tested on his competitive debut as the Red Devils cruised to a 4-0 victory over Queens Park Rangers at Old Trafford, but his weaknesses were highlighted against Leicester City at the weekend as he and his team-mates suffered a shock 5-3 defeat at the King Power Stadium.
In both games Rojo was deployed in the left-back role, a position that is soon to be occupied by fellow summer signing Luke Shaw. Manchester United paid more than £30 million to sign the England international from Southampton, and that's not the kind of money you shell out for a player to warm the bench.
Worryingly, Shaw's return to the starting XI will push Rojo inside to central defence, which is not an unfamiliar position for a player that operated in that area for former club Sporting Lisbon.
However, the Premier League is a huge step up in quality compared to the Portuguese Primeira Liga, and given the South American's somewhat shaky performances at Estádio José Alvalade over the years he is unlikely to bring much stability to Manchester United's already tremulous defensive line.
Unsettled back four
Tyler Blackett has been the only constant centre-back presence this season, the first academy product to really profit from Van Gaal's philosophy to give youth a chance at senior level. But, he's not looked particularly assured either, alongside a variety of different partners.
Rojo's positional play, marking and aerial ability are all attributes that have previously been called into question, and when Manchester United are crying out for an influential leader to marshal the back four, he is far from the type of character needed to improve their fortunes.
The 24-year-old's level of consistency should also be a major concern for Van Gaal, even more so during this current period of transition where all the players are under the spotlight following a disastrous downturn in form, ever since the retirement of Sir Alex Ferguson just over 16 months ago.
Summer spending spree
Manchester United took a scattergun approach to recruitment in the summer transfer market, seemingly ignoring the area of the squad that needed strengthening most significantly. The high-profile arrivals of Angel di Maria and Radamel Falcao are unquestionably good additions, but do very little to address their current problems at the back.
Ander Herrera is another more attack-minded midfielder, leaving Daley Blind as the man tasked with sitting, sweeping up and providing protection to the defensive line. However, he still needs better quality players behind him.
Many Red Devils fans still hang their hopes on England duo Phil Jones and Chris Smalling forming a solid partnership in the same ilk as the successful Rio Ferdinand and Nemanja Vidic combo, but if Van Gaal had much faith in that coming to fruition this season then why would he have splashed the cash on Rojo?
Injuries have prevented the Dutchman from trialling the pair together in a competitive match so far, and his apparent reluctance to deploy his recently-acquired World Cup finalist in the middle suggests he now has doubts about the player's ability too.
There's even been talk of Michael Carrick playing at centre-back when he finally recovers from injury after Van Gaal held "crisis talks" with the 33-year-old to sound him out as a possible solution to help mask United's clear defensive deficiencies, according to the Daily Mail.
Carrick's intelligence in possession and invaluable Premier League experience is viewed as an important asset after the disastrous capitulation which saw the Red Devils concede four goals in less than 30 minutes against Leicester on Sunday.
The former Tottenham Hotspur and West Ham star was utilised as an emergency centre-back by Ferguson in the past, but it's unlikely that Carrick will want to make a habit of playing there on a regular basis at Old Trafford.
Having only just returned to light training the veteran will not be available for selection when Manchester United welcome the Hammers to Old Trafford this weekend, with pressure mounting on Van Gaal to get back to winning ways.
With just five points from their opening five games the Premier League giants are currently sat in a lowly 12th place in the table, already falling away from early pacesetters Chelsea in the race for the title.
Like Rojo's prospects of becoming a successful centre-back in the English top-flight, the Red Devils chances of domestic glory in 2014/15 is, on the evidence provided so far, pretty implausible to say the least.