Answer:
(Fatwa: 267/267/M=1431)
It is makrooh to stand alone behind row. If the front row is complete and no one is expected to come, you can take back such a person from the front row who is aware of masayil and will possibly not spoil his salah.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
