Dylan Hartley has admitted that England will need to improve their discipline if they are to come out on top in next month's key Six Nations clash against Wales.
The Red Rose kept alive their hopes of claiming a Grand Slam success by seeing off Ireland 21-10 at Twickenham on Saturday evening.
Next up for Eddie Jones and his men is a potential decider against fellow unbeaten side Wales in a fortnight's time, but skipper Hartley believes that his side must work on certain areas of their game.
"The boss believes we left some opportunities out there and I fully agree," he is quoted as saying by BBC Sport. "I'm sure there's plenty to work on, discipline being top of the list."
England had both James Haskell and Danny Care sin-binned in the second half of their win against current Six Nations holders Ireland.
