The Toffees are currently competing with Arsenal for fourth place in the Premier League table that would ensure Champions League qualification, and Martinez has revealed that everyone at Goodison Park is collectively focused on achieving their target.
The 40-year-old is quoted by Sky Sports News as saying: "You only decide games on technical, tactical and physical aspects when they don't mean much.
"When there is a real meaning in every point that you play for, psychologically you need to be very strong, and probably that's a big advantage that we have, and we've shown that in the last seven or eight weeks.
"The team is focused, the football club is focused and we are very much all together fighting for the same aim. Psychologically we've got that winning mentality that you need."
Everton will move two points clear of Arsenal if they can win their fixture with Crystal Palace on Wednesday evening.