The Black Cats need the pair to rediscover their best form ahead of the final weeks of the season.
Sam Allardyce has admitted that both Yann M'Vila and Wahbi Khazri's performance levels have dipped in recent weeks, but has backed the pair to rediscover their best form as Sunderland continue their fight for Premier League survival, the Shields Gazette reports.
The two players enjoyed strong starts to life at the Stadium of Light, but have struggled to make such an impact in recent weeks, which has been especially noticeable given the club's position in the relegation zone.
But while Allardyce conceded that they have not been at their best, he suggested that they still have the quality to inspire the club away from danger.
"They have dipped off a little bit, but they'll come back again in the next five games, and there's other players to step in if they don't," he told the Shields Gazette.
Although Sunderland are in the bottom three currently, they have an advantage over both Norwich and Newcastle in that they boast a game in hand over the pair.
But with the likes of Arsenal and Chelsea still to play, the Black Cats will need the two men to get back near their best as quickly as possible as if they are unable to help the side compete in the middle of the park, their advantage over the sides battling near the bottom may be wasted, and their survival hopes could be severely dented.