He had to miss a game in Ottawa due to a minor injury, his wife's due date is also rapidly approaching, with their first born child on the way.
These two events, in combination with the fact that Samsonov is trying to give the Leafs a good push for the playoffs are most likely what contributed to his poor performance when he rejoined the Leafs in their recent game against the Islanders.
In a post-game interview, Ilya Samsonov explained that he was not all there mentally, stating that he had a lot of important things on his mind, and that he is flying back to Toronto to be with his wife.