Dele Alli's Tottenham return has been labelled "embarrassing" by Harry Redknapp after Everton were beaten 5-0 in north London.
Alli's career in the capital stalled and he finally moved away in January, teaming up with Frank Lampard at Goodison Park.
His fortunes have not improved though and he is yet to start for the Toffees, whose relegation fears deepened at Tottenham.
Lampard introduced Alli off the bench during the drubbing on Monday night and the 25-year-old was ineffective against his old club.
The former Tottenham man claimed working with the Everton boss, the Premier League's most prolific midfielder, was a major factor in his decision to move to Merseyside.
However Redknapp cited the huge downfall experienced by Alli in recent years as he returned to London.
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He told talkSPORT: “What’s happened to Dele Alli? Frank brought him in and was so excited about signing him, there’s got to be something wrong with what he’s doing as he can’t get in the team.
“He goes back to Tottenham last night and it’s almost embarrassing. He was such a big player and when you go back to your old club you don’t want to sit on the bench.
“You want to show them what you can do. He’s done nothing since he’s been there.
“I’ve been one of his biggest fans, but there’s a few of them that need to start performing as they are in desperate trouble.”
Tottenham found themselves 3-0 up by half-time and quickly extended their lead in the early minutes of the second-half.
It leaves Everton just a point above the relegation zone, although they do have games in hand on their rivals.
Jamie Carragher confessed that the Toffees could realistically go down such has been their poor form.
Lampard spoke candidly after the defeat insisting he could find few positives from the trip south.
He told Sky Sports: "We were well-beaten. We started alright for 15 minutes or so but we didn't deal with their counter-attacks well enough.
"At 3-0 it's horrible for any team to try and get back into a game because the momentum is completely gone. Individual moments of bad mistakes and bad defending.
"Before I came in there were issues, which are becoming more clearer to me every day.
"But the important thing as I lead it, is that the positivity stays. There's nothing positive about tonight, other than Anthony Gordon and a couple of performances of credit in terms of people that didn't give up."