ATLANTA — Pedro Martinez returned to the Dominican Republic to be with his sick father today, delaying his plans to test his ailing hamstring.

Martinez had planned to rejoin the New York Mets for a bullpen session today. But after arriving in Atlanta this morning from Port St. Lucie, Fla., Martinez learned his father, Pablo Martinez, had experienced a medical setback. Martinez then left to be with his father, Mets spokesman Ethan Wilson said Wednesday.

Martinez's 78-year-old father, Pablo, has a form of brain cancer.

Wilson said the team does not know how long Pedro Martinez plans to remain in the Dominican Republic.

The Mets had hoped Martinez could return before the end of the month, possibly for a series against the Los Angeles Dodgers from May 29-31. The 36-year-old has been on the disabled list since April 2 with a strained left hamstring.