Chelsea manager, Mauricio Pochettino has explained why Christopher Nkunku remained an unused substitute in their 2-0 win over Sheffield United on Saturday. Nkunku was named in the Blues’ matchday squad for the first time since he arrived from RB Leipzig in the summer. Cole Palmer and Nicolas Jackson found the back of the net as Pochettino’s men recorded a rare win at Stamford Bridge. The 51-year-old manager, speaking after the game, said he did not want to risk Nkunku for the game, with the player only just returning to full fitness following a substantial injury. He told BBC Sport: “We didn’t…