Etuhu is Sunderland's fifth new signing of a busy summer and Keane believes the tough-tackling midfielder will prove a valuable addition to his squad.
"I'm very pleased that Dickson has signed," Keane told the club's official website.
"He will add competition to our squad and give us a real physical presence.
"He's a big, strong player who can also get a goal.
"We're definitely heading in the right direction as far as getting the players we want to the football club.
"The signing of Dickson creates competition and a club like Sunderland needs that."