Birmingham boss Bruce excited by Oubina arrival
Bruce told the Birmingham Mail: "He will add some experience. You could see that at Middlesbrough in the centre we had (Fabrice) Muamba and (Johan) Djourou who, although cracking players, are only 19 and 20 respectively.
"Because of their physical size and presence, we sometimes forget that Muamba and Djourou are young and still a bit raw at times.
"Muamba, for example, showed us what he can do when he was against (Frank) Lampard and (Michael) Essien at Chelsea. But youngsters are going to be up and down."
Bruce added: "Oubina has a good pedigree and, with him here, it leaves me to toy with the idea of maybe changing our system.
"Whether you say I've been adventurous playing two up and two wingers, I don't know. But Oubina gives us another option, going that way of having three midfielders in there and a couple out wide supporting the front, or one off the front.
"Especially against the big teams, we've done well playing that way, like at Chelsea, and I might adapt us a little bit.
"That's not being negative, it's just something that tends to work for us, especially away from home."