I also thought Redknapp moved him from a #10 to LM; not deep (like he plays for Croatia in a 5 man midfieler) further forward.
Modric never played in a 5 man midfield for Croatia (until last week).
He played exclusively in the middle of a 4-4-2.
At Dinamo Zagreb he often played on the left or middle of a 4-2-3-1.