How does one who joins the imam in the last rak'ah sit?

The questioner : And likewise, if one is late by one rak'ah in a four-rak'ah prayer, how does he sit in the final tashahhud relative to the imam? And as for him, in the third rak'ah, does he sit in the tawruk position or the iftirash position?

The Shaykh : No, the tawruk position is only for the final tashahhud that is preceded by a tashahhud. So if the imam is praying the obligatory prayer, he must sit in the tawruk position just as the imam does. But in the middle of the prayer, there is no tawruk; it is only the iftirash position.