Danny Welbeck’s spectacular comeback on Sunday has given Arsenal’s prospects of success this season a significant boost, according to captain Per Mertesacker.

Welbeck ended a 10-month injury absence when he returned to action as a late substitute against Leicester and headed a last-gasp goal to earn his side a priceless three points.

The former Manchester United forward’s involvement means that only Jack Wilshere and Santi Cazorla remain on the Gunners’ long-term injury list, with both pencilled in to return next month.

And Mertesacker feels the availability of Welbeck and others who have recently rejoined the squad, including Alexis Sanchez and Francis Coquelin, could prove crucial as Arsenal chase honours on three fronts.

“For Danny, going through a bad period of injury, he kept believing in himself when maybe everyone doubted him,” said the Gunners defender.

“It was a great chance for him, to come in and show that he’s ready to give everything to the team. He was always integrated into the team but when you feature on the pitch it gives us such great energy and gives him a big lift.

“We need players coming back. We had a lot of long-term injuries and it gave us a bit of a struggle, especially in December and January where we played almost the same team [every time].

“Players who stepped in for other players gave us great energy but now we need players to come back and make the difference, which is very important as we saw against Leicester.

“With the long-term injuries there’s always a bit of a concern – when there are injuries for two, three or four weeks, you can cover that. But when three or four players have injuries for five or six months, it takes a lot of time.

“We are happy to have Danny back now and a few others not far off, so there’s more coming from them. We need all the players – you could see it makes a difference to have the whole squad.”

Arsenal’s victory over the Foxes’ 10 men, with Theo Walcott cancelling out Jamie Vardy’s opener, was the first time they had come from behind to win since the last meeting between the sides in September.

Mertesacker, who regained his place in the starting line-up at the expense of the injured Gabriel, regards the triumph as a strong indication of the mental strength among the Gunners squad.

“We kept believing, honestly,” added the former Germany international. “We had some bad finishing at times, especially in the box, but we kept doing our job and having a strong mentality no matter what happened.

“In the first half, how we defended and how we limited them to the break was good. That kept us believing that we could score against them.

“Obviously at 1-0 down, when they got a player sent off, it created a little bit more energy and belief. If you focus on the communication that gives you the bit of luck you need.

“When the referee blew the whistle for the final time it was a big relief – the energy that created was fantastic, for us, for the fans and for everyone at this club. Everyone is very focused now but relieved as well.”