Leeds United boss Marcelo Bielsa reportedly believes that summer signing Robin Koch is 'too soft' to excel in the Premier League. 

What are the concerns about Koch?

Football Insider has reported that both Bielsa and the Leeds coaching staff are concerned that Koch is 'too soft'. 

A source has told the website that the Argentine considers the defender to be a fine player but fears for his limited physical resilience.  

Koch apparently "doesn't like the aerial duels" and this weakness is considered to be a huge issue by the coaching staff.

The former Freiburg man was recently overlooked by Bielsa, who favoured the less experienced Pascal Struijk to start against Liverpool, as Liam Cooper was suspended. 

His softness was reportedly why Struijk got the nod over the summer signing.  

How has he performed this season? 

Following his arrival from the Bundesliga, Koch was one of Leeds' go-to defenders at the dawn of the season and made 11 appearances for the Yorkshire club between September and December. 

However, the positive start to his maiden season was soon met with a devastating blow. 

During Leeds' clash with Chelsea in December, the defender sustained a knee injury which sidelined Koch for 18 games, according to Transfermarkt

Following his return from injury, Koch has struggled to re-establish himself in the Leeds starting XI and has played just shy of 30 minutes of football. 

Is he being judged too harshly? 

Bearing in mind this is his first season in the Premier League, the German may simply need some time to adapt.

The English top-flight is infamously more physical and tough than other leagues across Europe, so it'll take some time for him to adjust.

As per Football Insider, Llorente is considered to be an outstanding defender by Bielsa, while Cooper is also deemed to be his greatest partner. 

It seems some minds have already been made up, meaning Koch is already facing an uphill struggle to prove his doubters wrong. 

Could Koch be sold this summer? 

There is nothing to suggest the German would be sold this summer but if Bielsa isn't convinced about the defender, then this doesn't exactly bode well for Koch. 

The Argentine's decision to include Struijk over Koch is an indicator that the seven-cap international has slipped down the pecking order at Elland Road. 

In addition to this, Koch is currently the club's second-highest earner with a £46,000-a-week wage, according to Spotrac

Therefore, it's not past the realm of possibility that the German may exit the club in the coming months - there's no point in him wallowing on the bench when Leeds are paying him comparatively big money.