The tour was recently scheduled to consist of one Test match and two ODIs, but both teams agreed to play a second five-match encounter and skip the 50-over games.
Sri Lanka are currently in New Zealand for their two-match series against the Black Caps and on Monday had their faint hopes of reaching this year’s ICC World Test Championship final dashed when they fell to a thrilling final-over loss to the Kiwis.
While the visit of Ireland will not be a part of the World Test Championship, it will provide Sri Lanka with some excellent practice ahead of the next World Test Championship period.
The five-day matches will also be important for Ireland, who have played just three Test matches in total over the last six years.
Their next three will now come in the space of two months, with Ireland travelling to Sri Lanka for two Tests and then taking on England in a one-off Test at the start of June.
Both Test matches between Sri Lanka and Ireland will be held in Galle, with the first contest commencing on 16 April and the second from 24 April.
Source: ICC