William Gallas claims he is ready to fill in at left back for new club Arsenal.
The France international left Chelsea for Arsenal at the end of the transfer window, with the defender citing a desire to play at centre half as the reason behind his exit.
Gallas was asked to play at full back on a number of occasions during his time at Chelsea and he could be set for a repeat at Arsenal.
Gunners chief Arsene Wenger has a problem at left back, with Gael Clichy sidelined with injury, and Gallas could be asked to fill in.
Although making it clear that he prefers to play at centre half, Gallas is ready to slot in at full back against Middlesbrough.
"I play to help my team," said the 29-year-old.
"If they have a problem at left back or right back I help them, that is normal - but everybody knows my best position."
Swiss star Johan Djourou is determined to make it hard for Gallas to claim a spot at centre half for Arsenal.
"Of course, Gallas comes in and he's a top player so I want to show that I have the quality to play as well," Djourou said. "I'm going to do everything to be fit and to play.
"Just by playing, Arsene Wenger shows he has confidence in me."