Wayne Rooney's failed effort from the spot in the contest at Old Trafford, blazed high over the bar in the 79th minute, leaves United with a record of four penalties scored and five missed for the season so far. Although it proved not to matter as the England international's first-half strike set up a fourth-round meeting with Fulham.
Asked about their penalty record after the game, Ferguson told MUTV: "I don't think it is just one of those things. I think we have to improve at that. If you get a penalty kick, really... there has been talk about (the good penalty record of) Rickie Lambert at Southampton. That is what taking penalty kicks is about."
He continued: "There have been several great examples over the years - (former Southampton midfielder) Matthew Le Tissier scoring 47 out of 48. A penalty kick is your opportunity to take advantage of a foul or a handball or whatever and score a goal."
A stand-out performer for United was veteran Ryan Giggs, who wore the captain's armband in a team showing 10 changes from Sunday's Barclays Premier League win over Liverpool.
Referring to the 39-year-old midfielder after the game, Ferguson said: "He will play for another year. There is no discerning signs of tiredness or weakness in his game, his quality is still there, he has fantastic balance and he has appetite for it. He is just an incredible human being."
West Ham boss Sam Allardyce lamented his team's inability to make the most of the chances that came their way, but also made it clear he was unhappy with referee Phil Dowd's decision-making with regard to the two handball incidents, and suggested the referee lacked courage.
Allardyce said: "It was very frustrating due to the fact that we have created so many opportunities to get ourselves back in the game, and then very disappointing that we were not given a penalty at 1-0 in the second half for Rafael's handball, which was blatant and clear for the referee to see in the position he was in.
"He couldn't find the courage to give it unfortunately, and he then went down the other end and there was a very similar incident with Jordan Spence and it was given. That is a very big disappointment for me - the lack of consistency in that area.
"But the frustration was that we really lost the game due to our lack of finishing quality. We didn't produce that when we had a great opportunity to do it on several occasions."
- Sports & Recreation