Chelsea manager Jose Mourinho has claimed Kurt Zouma proved himself during the victory over Tottenham Hotspur after replacing Gary Cahill's at half time at Stamford Bridge.
The Blues eased to victory through Eden Hazard, Didier Drogba and Loic Remy's goals, to remain six points clear of champions Manchester City at the top of the table.
Zouma replaced Cahill at half-time after the English international suffered a head injury earlier in the game after a clash with Spurs defender Jan Vertonghen.
But when questioned about it, Mourinho said: "He (Cahill) is ok. No concussion and he doesn't need special care. He was maybe just a bit afraid of heading the ball."
With defensive duo John Terry and Cahill unmoved in the heart of the defence, Zouma had previously made just one Premier League appearance this term, with starts restricted to the Champions League and Capital One Cup.
But Mourinho believes he proved against Tottenham he is ready to replace both Cahill and Terry whenever required in the coming games.
"It was a good opportunity for Zouma. It was very good for him. He is playing very well every time he plays. Today against Tottenham it was a good test for him. He will be a big player for Chelsea."
Meanwhile, the manager expressed his happiness for how the west London side overcame a difficult start to the game to secure victory.
"We played against a very good team and they showed that during some periods in the game," he added.
"They started better than us and should have scored before us, but after our first goal our team became more stable and confident and we controlled the game.
"I am really happy with the three points, performance and spirit of the players. It's too heavy a result, though, for Tottenham."