Danny Welbeck
Welbeck has scored seven times since joining Arsenal from Manchester United.Getty Images

Arsenal are set to be without Danny Welbeck and Olivier Giroud for the New Year's Day trip to Southampton, manager Arsene Wenger has revealed.

Welbeck suffered a thigh problem during the 2-1 win over West Ham United on Sunday and joins Aaron Ramsey, Mikel Arteta, Jack Wilshere, Mesut Ozil, and Serge Gnabry on the side-lines.

With Giroud set to serve the second of his three-match ban for head-butting Queens Park Rangers defender Nedum Onuoha on Boxing Day, Arsenal face being without their two first choice strikers for the visit to one of their rivals for a Champions League spot.

Theo Walcott is meanwhile expected to be available for the visit to his former club on Thursday, after Wenger said of the England international: "On the fitness front, he is ready to play."

Though Wenger does have other attacking options available to him, having handed Yaya Sanogo, Lukas Podolski, and Joel Campbell just two Premier League starts this season, the French boss clearly lacks confidence in the club's back-up forwards.

The news also means Chile international Alexis Sanchez will be deprived a much-needed rest after playing the full 90 minutes in his last 15 appearances for the north London club and was noticeably flagging during the win at West Ham.

Southampton have lost four of their last seven games, but after salvaging a draw against leaders Chelsea remain ahead of Arsenal in the final Champions League spot heading into the second half of the season.

Victory for either side will hand them the perfect start to 2015 and give them a three-point cushion over their rivals, with West Ham United and Tottenham Hotspur looking to make up ground on any dropped points.

"It's tight, very competitive [in the top four]," Wenger said of the race to finish in the top four. "You give your best, if there's a weakness you take advantage."