Leeds roped in the 25-year-old from German giants Bayern Munich last month to bolster their midfield, with the player putting pen-to-paper on a four-year deal at the club.
The midfielder started for Leeds in their Premier League opener at the weekend and played 73 minutes as they registered a 2-1 win over Wolverhampton Wanderers in front of a packed Elland Road crowd.
Roca was a bit-part player at the Allianz Arena and questions have been raised whether he is capable of making it in the Premier League, but Koch is confident the Spaniard can do well with the Whites.
Koch explained that Roca champions a fighting spirt in addition to being a technical player on the pitch, all qualities that means he is suited for Premier League football.
Asked whether he thinks Roca can make it in the Premier League, Koch told German magazine Sport Bild: “He’s a fine technician, but he also has it in his DNA to want to fight for every ball.
“Marc is not only a technician but also a fighter who suits the Premier League.
“He also speaks very good German.
“I told him to keep it that way.
“The important thing for him is to just get minutes now.”
Leeds are gearing up for their first away game of the season and will travel to St Mary’s Stadium to take on Southampton at the weekend.
