Depending on the league and the field size, either 4 or 7 players are allowed on the field for one team at once.
dᵻpˈɛndɪŋ ɔnðə lˈiːɡ ænd ðə fˈiːld sˈaɪz, ˈiːðɚ fˈoːɹ ɔːɹ sˈɛvən plˈeɪɚz ɑːɹ ɐlˈaʊd ɔnðə fˈiːld fɔːɹ wˈʌn tˈiːm ɐtwˈʌns.