Lehmann is no fan of the former Chelsea and Bayern Munich coach.
Tuchel kicks off his time as England coach tonight with their World Cup qualifier against Albania.
Lehmann says his fellow German is no "traitor" taking the England job, but can't see him succeeding. He told TalkSPORT: "For me, he is not a traitor.
"For me, he is very lucky to get such a great job. There must be a reason why he's not with Bayern Munich anymore. It's very difficult to get sacked by Bayern Munich.
"But we are happy for him that he's the English coach now.
"There's no such thing like being called a traitor. 'I heard that for the first time from Robert (Huth). I like Robert and like sometimes his clear views.
"It doesn't make England more likely to win anything, but it's good for him."