No 1 Alex McCarthy has joined backup Fraser Forster on the injured list leaving Ralph Hasenhuttl’s side without a senior goalkeeper.

But they have moved quickly to swoop for free agent Caballero, 40, who is set for a medical on Monday ahead of signing a short-term contract at St Mary’s.

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Forster was left out of Southampton’s squad to face Brighton on Saturday with a muscle problem.

The situation then worsened for Southampton when McCarthy suffered a hamstring injury during the game, with Hasenhuttl criticising him for not flagging up the issue before conceding a 98th minute equaliser.

Initial expectations are that McCarthy is expected to be side-lined for at least a fortnight.

The injuries could hardly have come at a worse time, ahead of the busy period of festive fixtures.

Harry Lewis, 23, is the only other option in Hasenhuttl’s squad but he has yet to make his Premier League debut and featured only three times for Southampton with all of his appearances coming in the FA Cup during the 2016-17 season.

In contrast, former Argentina goalkeeper Caballero is considerably more experienced at the highest level.

He has played 86 times across seven seasons for Manchester City and Chelsea, with 34 of those appearances coming in the Premier League, and also played top-flight football in his native Argentina and Spain.

Caballero has been without a club since leaving Chelsea at the end of last season but been maintaining his fitness with a view to returning to football and spent some time training with League One AFC Wimbledon. (AF)