Smalling has been used in several positions for both club and country, but the Old Trafford defender, who started for England in their 0-0 draw with Costa Rica on Tuesday, is keen to hold down a regular position in the centre of Roy Hodgson's defence.
The 24-year-old is quoted by ITV Sport as saying: "It's the end of the season so obviously we will go on a break now and then next season, I will look to really kick on to try to cement my position.
"Roy knows that I am a centre-back and I really want to cement it and be that number one. I feel that if I get my chance like I did against Costa Rica, I can go out there and deliver."
Smalling has made 13 appearances for England since his international debut in 2011.