He said after the 2-1 win over Nigeria: "I think we've been pretty clear for a fair while, but there is real competition for places in certain areas of the pitch".
The number one question facing Gareth Southgate is who will be England's No. 1, but the Three Lions coach remained tight-lipped on who he is leaning towards.
Gary Cahill and Harry Kane put England ahead after findng the net in the seven and 35 minutes of the first half.
Alli (whose full first name is Bamidele) was eligible to represent the African nation through his Nigerian father, but chose to throw his lot in with England where he was born and has lived all his life.
Just as England never recovered from a bad start four years ago, a positive result early on - maybe in the first game, maybe as early as the upcoming friendlies against Nigeria and Costa Rica - can help generate the sort of momentum that enables a team to grow in a tournament.
Jordan Pickford started against the Super Eagles, with Jack Butland likely to be next in line, but Southgate says there is still all to play for.
Both of England's opponents have qualified for the World Cup and their differing styles will offer Southgate a glimpse at how his players will cope with the varied approaches they will face in Russian Federation.
'We were deservedly two goals up in the first half.
The England chief continued: "The second half, it would be easy to say we were complacent".
Simon is expected to spend at least three weeks on the sidelines, and the decision to leave him out means coach Gernot Rohr now has two more players to drop from his remaining team of 25.
It was certainly an introduction to remember for Nigeria's raw teenage keeper Uzoho who emerged as the No1 choice after Carl Ikeme had to stop playing after being stricken with cancer.
"It was unbelievable to get on the pitch, that's all we work for is to be on the pitch week in, week out, and it was just really nice to get on the pitch and get the win". There were concerns that the 21-year-old would sit out the World Cup with the problem, but while he has moved to eased fears of any potential absence, Nigeria lacked the youngster in the middle of the park at Wembley.
Sterling has made huge strides in Pep Guardiola's record-breaking title winners at Manchester City, scoring 18 league goals and fulfilling his rich potential in the most prolific season of his career.
Having experienced former England team-mates Nobby Stiles and Mike Summerbee being affected by the disease, Hurst hopes to play his part in helping raise funds for research into prostate cancer, which kills one man every 45 minutes.
A little more trial and error from England manager Gareth Southgate, trying to fit Alli, Jesse Lingard and Raheem Sterling into the same starting eleven.