Clarke feels Sessegnon will add much needed pace to his attack.
"We needed to strengthen in the forward areas and we're very hopeful that Stephane and Victor (Anichebe) will fit the bill," he told the WBA website.
"Stephane is quick and direct and can be a match-winner. He has the individual skills that can turn a game.
"He creates chances for others as well as scoring his fair share of goals."
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