The American signed a new deal with Spurs yesterday.
Friedel told talkSPORT: "He is a very nice guy, very impressive.
"I met the rest of the staff [as well] and they seem a very tight-knit unit. I was well impressed with everything I heard.
"A lot of us were saying that over the last 18 months Southampton were one of the hardest teams to play against and that is obviously a lot down to him. I'm very excited to start [working under him]."
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