Liverpool are facing a goalkeeping crisis ahead of the Premier League trip to Southampton after Adrian was injured by a supporter during the UEFA Super Cup celebrations in midweek.
The Spaniard, who was a hero in the 5-4 penalty shootout victory over Chelsea after saving Tammy Abraham's penalty to clinch the win, has a swollen ankle caused by the fan sliding into him after trying to evade security at Vodafone Park in Istanbul.
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Jurgen Klopp, who is already without first-choice goalkeeper Alisson due to a calf issue, revealed it is not "100 percent clear" whether Adrian can feature at St Mary's.
"When we were all together, a supporter jumped over, was chased by some security guys, slipped and kicked his ankle," Klopp told a news conference. "Crazy! Yesterday it was swollen and today I spoke to him and he said it's much better, but we have to see.
"He couldn't have played directly after we landed in Liverpool, but I saw him now he's better."
Adrian was unexpectedly drafted into action during the first half of the 4-1 win over Norwich on the opening day of the Premier League season after Alisson limped off.
The former West Ham keeper -- recruited as a free agent on Aug. 5 -- wasn't afforded time to settle before featuring, but Klopp saluted the player's "big personality."
Andy Lonergan, who trained with Liverpool during their preseason tour of the United States, was signed on a short-term deal as experienced cover earlier this week with highly rated young keeper Caoimhin Kelleher shaking off a wrist injury.
Asked if Lonergan or the 20-year-old could start against Southampton, Klopp said: "If we have to make a decision, then we make a decision.
"Caoimhin is a boy we are all excited about. He's now in training, but not 100 percent yet. He has to be in training today, then we will see."
Meanwhile, Naby Keita will sit out the game due to a hip muscle injury, which Klopp labelled minor but could not put a time frame on the midfielder's return.