Guevarra, who is also an ex-officio member of the Judicial and Bar Council (JBC), said the two magistrates filed their acceptance of their nomination following the retirement of Chief Justice Teresita Leonardo-de Castro on Wednesday.
Meanwhile, Senior Associate Justice Antonio Carpio has yet to make a formal acceptance of his nomination.
Carpio earlier said there is "no legal impediment" for him to be included on the shortlist but he has yet to send the paperwork confirming his acceptance of his inclusion in the names to be considered.
The five most senior justices of SC are automatically nominated for the Chief Justice vacancy under the rules of the JBC, the seven-member panel tasked to screen nominees for judicial posts.
Apart from Carpio, Peralta and Bersamin, the other most senior SC justices are Associate Justices Mariano del Castillo and Estela Perlas- Bernabe.
Carpio will reach the mandatory retirement age of 70 for the judiciary in October next year.
The Constitution requires associate justices to be a natural-born citizen, at least 40 years old, engaged in the practice for at least 15 years and a person with proven competence, integrity, probity and independence.
Duterte has appointed six justices so far, the latest of whom is Court of Appeals Associate Justice Ramon Paul Hernando.
His other appointees to the High Court are Noel Tijam, Andres Reyes Jr., Alexander Gesmundo, Jose Reyes Jr., and Ombudsman Samuel Martires.