Albion defender Jonas Olsson is poised to sign a two-year contract extension as the defenders at the Hawthorns were warned of a new threat to their places.

The vice-captain will sign an improved Hawthorns deal until the end of 2012/13 season, replacing a current contract that was due to expire at the end of next season.

Olsson said: “I had two years left and will sign for an additional two. There are just one or two things left to sort out, but it should happen soon.

“I really enjoy it at the club and have got a great deal. I have an important role in the team and it feels good to have the support from the new manager. I feel that I am one of the cornerstones of the team.”

Chile international Gonzalo Jara is standing by for his League debut against Crystal Palace tomorrow, when he is likely to fill in at left-back for the injured Joe Mattock alongside Olsson.

But Jara, aged 24, has played for his country at centre-back and right-back and fellow Baggies defender Gianni Zuiverloon is expecting a concerted challenge from the Chilean.

Zuiverloon said: “I think he is a very good player. He is a Chile international.

“Competition is always good for you. If you have competition you will train and play better to keep your position.

“It is always good to have competition and it’s even better because he can play across the whole back four, or as a defensive midfielder as well.”

Zuiverloon, who will keep his spot at right-back tomorrow, reckons Jara has settled well to life at the Hawthorns, including a debut in the Carling Cup at Arsenal on Tuesday.

The Dutchman said: “He is a happy guy. He is always laughing and making jokes and I think the team also likes him.”

Zuiverloon has been part of a clear improvement in defence under new head coach Roberto Di Matteo. The young defender has enjoyed his first taste of Championship action.

He said: “I actually haven’t played many games, but I played against Newcastle and Middlesbrough, which were like Premier League games and weren’t that different.”