Coates signed for the Reds this week from Nacional Montevideo.
"He's a full international and Uruguay are amongst the top five in the world, so they're a strong international team," Clarke told the club's official website.
"He's a talented youngster and gives us different options at the back. He's ready to play if required, but we've also got many other centre-halves ready to play if required.
"You never really know how a foreign player coming into the English game is going to adapt. Some take a long time to adjust, while others like Luis Suarez come in and settle straight away."