The Paraguay international has made 10 league appearances for Newcastle so far and sustained the injury in the second half of their victory over Southampton on Saturday.
"Miguel Almiron will miss the rest of the season after suffering a hamstring injury in Saturday's 3-1 win over Southampton," Newcastle said in a statement.
"The 25-year-old was withdrawn in the 64th minute against the Saints and having been assessed by the club's medical staff, it has been confirmed that he will not be fit for the Magpies' final three matches of the campaign."
Newcastle said they were in touch with the Paraguayan Football Association's medical staff and that Almiron might still be able to represent his country at Copa America, which starts on June 14.
(Reporting by Simon Jennings in Bengaluru; editing by Amlan Chakraborty)
