New head coach Mark Sampson has lifted the England squad since replacing Hope Powell in December, says Toni Duggan.
Sampson drew his opening friendly with Norway and leads defending champions England into this week's Cyprus Cup.
England open their campaign against Italy on Wednesday and Manchester City striker Duggan told BBC Sport: "There's been a boost in the players' mentality.
"Mark has brought in a lot of new faces and that brings better competition for places and brings us on as players."
Although the Cyprus Cup is a friendly tournament, it will offer a sterner test than England's recent World Cup qualifiers.
Under caretaker boss Brent Hills, England won all four qualifiers without conceding a goal but in Group A in Cyprus they will also face Finland and Canada, the team they beat in last year's final but who are four places above them in Fifa's rankings.
Scotland are in Group B and also start their tournament on Wednesday against France, who beat England 3-0 during their disastrous Euro 2013 campaign and are the Cyprus Cup's top-ranked team.
The Scots also take on the Netherlands and Australia, with the winners from Group A and Group B contesting the final on 12 March.
England's record goalscorer Kelly Smith has been recalled to the squad for the first time since Euro 2013 after injury, while captain Casey Stoney will miss out because of a foot problem.
Duggan, 22, was one of the few England players to come out of the Euros with credit but will face competition for her position from the likes of Lianne Sanderson, who was recalled to the set-up following a fall-out with Powell.
Duggan added: "We want to retain our title. It's always good to get games under your belt and have that competitive edge.
"I'd love to be [the main striker] one day, but as long as I am playing for England, whether that be a striker or a wide player, I'm happy, and I hope I can impress Mark this year and leave the decision in his hands."
England return to their 2015 World Cup qualification campaign in April against Montenegro and have five further games remaining.