With William Gallas out of contract in the summer and Johan Djourou recovering from serious knee surgery, reinforcing the Gunners defence is a priority.
And Wenger, who prolonged Campbell's career earlier this season when he walked out on Notts County, admitted: "We are in need there.
"Gallas can sign where he wants. We are trying to re-sign him but he is legally free to sign where he wants so I don't know where he will go.
"I will have to sit down with Sol Campbell because if he is on board, if he is focused and motivated, he is an important player here.
"He is not only an important player and a good player but he is a winner."
Wenger believes Campbell's performance in the defeat against Tottenham on Wednesday, even though the result virtually put paid to their title hopes, epitomised what the defender brings to the club.
"He was ready to die on Wednesday night to win the game and that is what you want from your squad," Wenger added.
"On and off the pitch he is a big influence."
The Gunners travel to relegation-threatened Wigan on Sunday and striker Robin van Persie could get his first start for five months if he recovers from muscle tightness following his return as a substitute against Tottenham.
And while Wenger concedes title ambitions are no longer realistic, he maintains it is important to lift morale and refocus on winning the major trophies next season.
He said: "Overall this team has gained a lot of credit and done extremely well so it is important that we do not get a negative vibe now.
"Our season will be judged on how well we finish and that is why we play a vital game on Sunday."
Wenger also believes Cesc Fabregas will be at the club next season and dismissed the constant speculation linking his captain with Barcelona.
Despite Cristiano Ronaldo having moved from Manchester United to Real Madrid last summer, Wenger reckons a switch to Spain, even to the reigning European champions, is a step down for any top Premier League player.
He said: "If you are really competitive, you stay in England.
"That is where the competition is and that is where the best players want to be. I have so many calls from Spanish players who want to join us and want to come here.
"We want to keep this team together and improve from season to season. I believe we have made a big step forward considering last season and we want to do that again next season."
Injuries at crucial times wrecked Arsenal's title hopes this season but Wenger, who admits the pressure is mounting, insists his side are getting closer to adding their first trophy since they lifted the 2005 FA Cup.
He said: "I felt this year I must win a trophy and we were very close. It will be a decisive year next year for this team, that is for sure.
"The future of our team lies in how well we can respond to big disappointments and there's a good opportunity on Sunday to show that."