Liverpool must replace Simon Mignolet, move for No. 1 - Steve Nicol

Liverpool will need to upgrade from Simon Mignolet this summer and ideally find someone who can push Loris Karius to be their No. 1 goalkeeper, according to former Anfield defender Steve Nicol.

Karius became manager Jurgen Klopp's first-choice keeper in January and has conceded 10 goals with six clean sheets in 12 Premier League appearances this season.

Mignolet, meanwhile, has conceded 24 goals with seven clean sheets in 19 league appearances, but has not started since a 2-1 victory away against Burnley on Jan. 1.

He started Belgium's friendly against Saudi Arabia on Tuesday, a 4-0 victory in Brussels, and said afterward that he will think about his future after the World Cup this summer.

But ESPN FC analyst Nicol, the former Scotland international who won four league titles and one European Cup at Liverpool and was the 1989 Football Writers' Association Footballer of the Year, believes the club shouldn't wait for Mignolet to make a decision and should instead take their own initiative.

"I think Liverpool should go and see if they can either get a No. 1 or have somebody who's on a level with Karius because Mignolet isn't," Nicol said. "He ... is clearly the No. 2, and I think what Mignolet's doing is waiting to see if he can get a game in the World Cup.

"[Thibaut] Courtois has had a couple little injury nicks recently, and a good World Cup will mean Mignolet is in the shop window and he could get himself a good move."

Liverpool's defence was one of their main problems at the start of the season, but the signing of centre-back Virgil van Dijk from Southampton in January stabilised a unit that has the club in third in the Premier League and the quarterfinals of the Champions League.

"Liverpool's problems were always the defensive unit -- and by that, more importantly, the centre-back position and the goalkeeper," Nicol said. "They've certainly made a difference signing Van Dijk at that centre-back position, and Karius, as good as a last couple of months as he's had, are we really 100 percent relying on him? I'm not ready for that yet. That means Liverpool, in my opinion, have to go out and get a recognised No. 1."

Liverpool could turn to Italy for Karius' competition, including Roma's Alisson Becker, the Brazil No. 1, or AC Milan's Gianluigi Donnarumma. Nicol believes either would be a clear upgrade on Mignolet, who is under contract until summer 2021.

"I would have no problem with [Alisson]," Nicol said. "I wouldn't have a problem if they could get the likes of a Donnarumma, who could be the goalkeeper for the next decade.

"I think, definitely, it's a priority now for Liverpool. It's a weak spot. Again, as good as Karius has been recently, he's not the finished article by a long way."