Olivier Giroud
Giroud has not started a game for Arsenal this season. Getty

Arsenal defender Laurent Koscielny admits Olivier Giroud's return to the first team could be blocked by the form of Alexis Sanchez.

After returning to the club late this summer following an extended break after Euro 2016, Giroud has been unable to regain his place in Arsene Wenger's starting XI.

The France international has failed to start a game this season, with his woes compounded by a toe injury picked up in the Champions League clash with Paris Saint-Germain – a game in which he was sent off.

While he came off the bench in the final 10 minutes of the 3-0 win over Chelsea, the striker was not available for Arsenal's trip to Burnley last Sunday.

Giroud was subsequently left out of the France squad for upcoming World Cup qualifiers against Bulgaria and Holland.

Leading the line instead of him has been Sanchez, whose run of five goals and four assists in seven appearances has left him droppable.

"It is a delicate situation for him," Koscielny said of his teammate. "We came back late following the Euros. We joined the squad at another time. It took us more time to get fit.

"Olivier needed a little more time than others. There is a lot of attacking competition at Arsenal. Alexis Sanchez is playing exceptionally well so it is complicated to replace him in the starting XI."

He added: "I know Olivier and he has experienced much worse. We know his mental strength. One season is very long so he will have his chance during the following weeks. He'll then have to answer the call."

Giroud is likely to have returned to full fitness following the international break, with Wenger also hoping to have Aaron Ramsey available again by the time they host Swansea City in their next game on 15 October.