Qa’dah and Salaam

Reciting Sallallahu Alayhi Wasallam instead of the durood in Salaah

Q: If we are short in time when praying salat, instead of reading the whole "Allahumma salli `ala muhammadin wa.." in Durood, can we suffice with just "Salla allahu alayhi wa sallam", will the sunna be fulfilled by this? Also, is it ok to just mention the Prophet as a pronoun or should he be mentioned by name i.e. "Salla allahu ala Muhammedin wa sallam"?