There has been a shift in power in north London over the last couple of years.
Spurs have been title challengers all season this term while Arsenal have struggled to keep pace with the top-four.
Ex-Everton and England midfielder Osman insists Tottenham are now a much more enticing move for any potential targets.
He said: "If I was a player coming to the Premier League now I'd rather sign for Spurs than Arsenal.
"They are improving every year, there is a plan in place.
"Arsenal are in freefall. They are drifting."
Tottenham beat Arsenal 2-0 at White Hart Lane today to keep up the pressure on Premier League leaders Chelsea.
Dele Alli and Harry Kane netted for Spurs to cut Chelsea's lead back to four points.
