Translation:There are eleven people in a soccer team.
It can be both, but English generally uses "on" for players in the team and on the field. It also depends on what group of people you are talking about, such as on the team, on the field, in the outfield (baseball), in the stands, in the band, I don't know how to characterize when you'd pick in vs. on for these situations.
As far as I have understood a subject/object in nominative/accusative of a number 5-20 is always in the genitive plural form. Now it seems to me that человек is nominative singular. Why is this the case? Does it have to do with the fact that люди is not a real plural of человек (=there is no genitive plural)? Would be cool if somebody could explain these special cases :)
It seems that I was right, and there is some lost consistency in the word человек that used to be there! You can check this.
Люди is an irregular plural for человек, and человеки is regular but "Rare, poetic, except for the genitive plural челове́к"
BTW Genitiv "пять человек" is marked with a triangle as well, that's why пять людей may sound "more" correct to some people :)
It follows the standard adjective pattern, so -ый is the base (masculine) form, and -ой is the form used in all the feminine singular cases except for nominative and accusative.
So in this exercise, в means the case is prepositional and команда is a feminine word, hence the -ой adjective ending.
No that's not it. Rather, it's following the strange rules that Russian uses for numbers. If the last word in the number is "one" the following word will be nominative singular. If the last word is "two", "three" or "four" then you get genitive singular, and otherwise it's genitive plural. That's why no form of люди is used in this case.