Goals from Nathan Dyer, Gylfi Sigurdsson and Marvin Emnes sent the Merseyside outfit crashing out of the competition, but Martinez was content that a number of his first-team squad improved their match fitness at the Liberty Stadium.
The 41-year-old is quoted by BBC Sport as saying: "The scoreline reflects the team that took the chances. During long spells, we stopped Swansea from playing. It was an important game for us - for players who haven't played many minutes and to see where they are.
"If you analyse the chances Swansea had, they were few and far between. We had two or three very good situations. In many aspects, I was fairly pleased with that."
Everton return to action on Saturday lunchtime when they make the short trip to Anfield to face rivals Liverpool.