Duffy’s capture on loan from Brighton was hailed by many as one of the best signings in Scottish football last summer but it turned out to be a nightmare for the player and Celtic.


The centre-back made crucial errors, never looked settled in Scotland and eventually he was sent back to Brighton early from his loan after picking up an injury.



Foster pointed towards the shoddy recruitment Celtic carried out last summer that has led to much of their problems this season.


He insisted that Celtic’s style of football needs a centre-back who has pace to burn, but they went on to sign Duffy who, while an experienced defender, did not have the quickness of feet and was more used to defending deep inside his penalty box.



Foster said on the Go Radio Football Show: “Was it [Vasilis] Barkas, [Patryk] Klimala, [Albian] Ajeti, £13m for those three players? That doesn’t include the money they spent on Shane Duffy’s loan.


“Celtic in most games dominate the ball so the two centre-halves pretty much play on the halfway line most of the time.



“So, to be a centre-half at Celtic you need to be quick and they signed Shane Duffy who is an experienced centre-half and had a great career but he is used to defending his box. He stands on the edge of his box and defends it.


“As soon as you get him up the pitch and it’s a foot race, he couldn’t handle the pace of the Scottish game, especially a lot of it is all blood and thunder and you know it’s 100 miles an hour all the time.


“So, whoever thought that’s a guy who could fit into this team, I don’t see it.”


It remains to be seen what Brighton boss Graham Potter does with Duffy during pre-season.