Arsenal boss Arsene Wenger expects another cool performance from Thomas Vermaelen for tonight's clash at Portsmouth.

It will be a new experience for Vermaelen, who has settled quickly alongside William Gallas since his £10million summer move from Ajax.

Wenger believes the mild-mannered Belgian has led by example.

"Thomas is a very quiet boy, but very determined," said the Arsenal manager.

"I believe you see in every ball he plays. He is a good mixer with commitment and relaxed focus.

"That is very important when you play at the back, that you never panic - because panic is something which is contagious and he always looks to master that."