Arsenal manager Arsene Wenger will make signing a goalkeeper his priority in the upcoming summer transfer window and should launch a bid for Chelsea's Petr Cech or Manchester United's Victor Valdes if the pair become available, according to Charlie Nicholas.
Wenger has rotated David Ospina and Wojciech Szczesny this season but neither stopper has been able to inspire the club to a genuine challenge for the Premier League title.
Questions remain over both players' ability to be Arsenal's long-term answer between the sticks and Nicholas has urged Wenger to make reinforcing the position his primary objective in the summer window.
"My opinion is that Wenger will go into the market but the only area he'll be considering is a goalkeeper," he told Sky Sports.
"David Ospina is a decent goalkeeper but decent goalkeepers don't win you titles. If an opportunity for Cech, Casillas or Valdes comes up then they have to take it."
Cech has made just six Premier League appearances this season for champions Chelsea since Thibaut Courtois's return from a three-year loan spell at Atletico Madrid, with reports persisting that the Czech Republic international is ready to leave West London.
Since moving to United in January, Valdes has not made a single appearance for United this season as he continues to regain full fitness following a serious knee injury and though he agreed an 18-month contract at Old Trafford his future is uncertain.
Casillas meanwhile is entering the twilight of his Real Madrid career however manager Carlo Ancelotti does not expect the Spain captain to leave the club this summer.
However, as Cech continues to be linked with a move to north London former United defender Gary Neville does not believe the player will be allowed to leave for a domestic rival.
"If I was Jose Mourinho, with Arsenal potentially being one of my biggest rivals next season, I would not sell them Cech at all. It lets Arsenal off the hook," he said.
"You could argue they have struggled for a goalkeeper since Jens Lehmann and David Seaman. It's a struggle to win a title without a great goalkeeper, a massive struggle."