1) If a person arrives in the synagogue when the congregation have already started saying the blessings of the Shema, and he has no time to say the verses of praise even with some omissions, he should commence the blessings on the Shema with the congregation, pray the Shemoneh Esrei with them, and after the prayers he can say the verses of praise without Baruch She’amar and Yishtabach. (Shulchan Aruch 52)
2) Some say that one should never entirely omit the verses of praise, and if he has no time to say even Baruch She’amar, Ashrei and Yishtabach before praying with the congregation, he must say them before praying, even if by doing so he will be forced to pray by himself. (ibid)
