Wales midfielder Aaron Ramsey, who had been in superb form before his thigh injury on Boxing Day, marked his return to fitness with a goal in the 3-0 win at Hull, when German playmaker Mesut Ozil was also fit again following six weeks out because of a hamstring tear.
With England forward Theo Walcott set to miss the World Cup with the serious knee injury and Jack Wilshere also currently on the way back from a fractured foot, Arsenal have certainly seen their squad stretched.
Campbell - a bedrock of the Invincibles championship side from 2003/2004 - believes with a few more high-calibre players for manager Arsene Wenger to pick from, there is no reason why his old team cannot last the distance in the Barclays Premier League title race once again, having faded badly since the turn of the year after going out of the Champions League to Bayern Munich.
"You have got to get to the stage where teams are frightened of you
You need options and they could do with a few more players who could frighten other teams with their playing ability," said Campbell, speaking at an Independent Arsenal Supporters' Association question-and-answer session to help promote his new book, Sol Campbell - The Authorised Biography.
"It will turn, but you need that cutting edge in your side
The board might have to put their head on the block and go for it and do not be scared.
"If you spend money on a player and it does not work, you have to go again.
"Yes you can get players through scouting around the world, but ultimately these players are ready made and you have got to play top dollar to get them in.
"Arsenal need some more players who are ready-made and world-class
With everyone fit, I think they need another three players."
Campbell added: "Injuries have not helped Arsenal this season
Who knows, if Aaron Ramsey was fit, Theo Walcott did not get injured and Jack Wilshere played more regularly, you never know.
"They could be in a situation like Liverpool, who have not had many injuries."
Arsenal will tackle Hull at Wembley in the FA Cup final on May 17 looking to finally end a near decade trophy drought.
Wenger insists his men - who before then are aiming to secure a top-four finish, with Newcastle coming to the Emirates Stadium on Monday night - will be fully focused.
Campbell knows from first-hand experience the dangers of taking anything for granted in the world's oldest knockout competition, having been part of the 2008 Portsmouth side which beat Manchester United at Old Trafford and went on to lift the trophy.
"In the quarter-finals we played against Manchester United, they were confident, but in the FA Cup you never know
We were not expected to win anything that season at Portsmouth," he said.
"Hopefully Arsenal can heed that and realise that you have to earn it.
"Do not think 'here is the FA Cup'
Hull will have a different game, so hopefully Arsenal will understand that."
Campbell played more than 200 games for Arsenal over two spells at the north London club, having first joined in a controversial switch from Spurs in 2001, and won 73 caps for England at two World Cups before he finally retired from playing in May 2012
The 39-year-old maintains he is keen to one day return to football, but only at the right time.
He added: "I know I have to do the (coaching) badges
I know I am not ready now, but I know I am going to have to do it.
"I am very tactical and like breaking teams down in my head, like a chess board
I love characters as well.
"Football is a beautiful game
I have had a fantastic time playing
"As a manager, if I really go for it and am really committed, I will really go for it.
"I want to win everything I did not win as a player
I want to be ready.
"Sometimes I think players go from having a long career, straight into management and they are burned out.
"It is full on and maybe I am not ready for that yet
I know that, when I am ready, I have got everything in place.
"If I have to go abroad to start things, I will do that."
Source : PA
Source: PA