Celtic have work left to do in the transfer window as they look to bolster numbers in their hunt for the Scottish Premiership title. Nicolas Kuhn is to date the only arrival at Parkhead this month in a quiet window across the board, with many sides across the country prepared to wait until the end of January to do business. The former Germany Under-20 international is in line for his debut this weekend when the Bhoys take on Ross County at Parkhead. Rodgers clearly has a squad capable of competing for the title; nevertheless, fans will be desperate for one or two additions to provide an edge i…