The 35-year-old Moreno has been recalled to the Italy squad after a six-year absence, while Kayser is among 11 uncapped players in a France squad heading for Australia.
Italys national coach Nick Mallett has called Moreno into his squad in preparation for Tests in South Africa and Argentina six years after winning the last of his four caps for the Azzurri.
Moreno gained three caps for Argentina before moving to Italy and was capped in the 1999 Rugby World Cup and then in the 2002 Six Nations, but has not been called upon since.
Kayser is named in a 26-man France squad which will be without players involved in the Top 14 play-offs for two Tests in Australia.
Ben Kay has been named on Englands bench for the first test against New Zealand on Saturday, while Geordan Murphy is among the Ireland replacements for their match against Australia.
Marcos Ayerza, who gained his 16th cap for Argentina in the win over Scotland last weekend, retains his place in a 28-man squad for the second Test on Saturday.