Arsenal defender Per Mertesacker has said that Hector Bellerin has been a great addition to the back four this season.

The 20-year-old scored the opening goal as the Gunners beat Liverpool 4-1 on Saturday.

Mertesacker admitted that Bellerin has impressed him after stepping in as a result of Mathieu Debuchy's injury problems.

"He's given us a lot of energy this season," Mertesacker told Arsenal's official website. "He's stepped up because we've had a lot of injuries but he gave us such a great energy and he's capable of producing great performances.

"To put in such a good performance in front of our fans makes me delighted. I'm proud of our performance because we we kept going. It was a hard-fought win in the end and we deserved it with the way we played."

Bellerin has netted two goals in 20 appearances this season.