They were teammates at New York Red Bulls before the defender's move to Bolton last summer.
Ream, 24, said: "I've messaged him after just about every game so far. I've talked to him once or twice a week.
"He's just Thierry, giving good advice and telling me to keep my head up and keep plugging away.
"I'm sure he'll send a message about Tottenham to give me some pointers. Will he want us to win? I'm sure he will."