Team Ninja has explained why 'Ninja Gaiden Black' and 'Ninja Gaiden 2' can't be included in the 'Master Collection'.
The developer announced the remastered franchise in February, but two titles won't be featured due to the inability to "salvage the varying assortment of data" left behind.
Producer Fumihiko Yasuda told GameSpot: "We did consider it, but we were unable to salvage the varying assortment of data we had left from 'Ninja Gaiden Black' and 'Ninja Gaiden 2.'
"However, when we worked on 'Sigma' and 'Sigma 2', we went and collected as much of that data as possible and organised it.
"And since we could fully utilize this data, 'Sigma' and 'Sigma 2' became clear choices for [the 'Master Collection']."
Yasuda added that the three games which will be included - 'Ninja Gaiden Sigma', 'Ninja Gaiden Sigma 2' and 'Ninja Gaiden 3: Razor's Edge' - also make the most sense for the release.
He explained: "[They] represent the latest instalments of the numbered series and they are also the most polished versions featuring many additional modes and costumes."