Sessegnon has overcome a groin problem, while Yacob is back in contention to feature following a hamstring injury.
Both players have returned to training ahead of this weekend's meeting with Manchester United, but defender Billy Jones is unlikely to feature until April due to a hamstring tear.
"Stephane Sessegnon and Claudio Yacob are both in contention for Saturday's home date with Manchester United," read a statement on West Brom's official website.
"Sessegnon was left out of the last match against Fulham as a precaution after being sidelined for six weeks with a groin problem.
"Yacob also missed the 1-1 draw after suffering a hamstring problem against Chelsea, but both players will be involved in full training this week.
"Jones limped out of the Fulham game with a hamstring tear, an injury which usually sidelines a player for at least a month."
West Brom have still yet to win under Mel, who was appointed as the successor to Steve Clarke on January 9.
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