The American recently celebrated the one-year anniversary of his marriage to model Brooklyn Decker, who was on the cover of the Sports Illustrated Swimsuit issue in February.
Roddick also skipped Rome last year when he took a break after the wedding, meaning he doesn't have any ranking points to defend in the clay-court tournament, which begins Sunday.
While this tournament is mandatory for top-ranked players, Roddick will not be fined because he is allowed one free exemption per year as a veteran who has played more than 600 matches on tour.
The ATP said Roddick was expected to be back for the Madrid Masters on May 9. Both the Rome and Madrid tournaments are key warmups for the French Open, which starts May 23.
Roddick also skipped last week's Monte Carlo Masters, although that tournament is no longer mandatory for the top players. In the last tournament he did play, Roddick won the Sony Ericsson Open in Key Biscayne, Florida, three weeks ago.
Fourth-ranked Juan Martin del Potro and No. 6 Nikolay Davydenko will also not play in Rome _ both due to long-term wrist injuries.
Top-ranked Roger Federer, No. 2 Novak Djokovic and No. 3 Rafael Nadal are all expected at the Foro Italico, which will debut a new 10,500-seat stadium this year.
Federer has reached the final twice in Rome but has never won. Djokovic took the title in 2008 and Nadal has won four of the past five years.