The 18-year-old has been on loan with the Midlands side himself since the start of the season.
And he took to Twitter after confirmation that Aston Villa's experienced midfielder will link up with him and the rest of the Coventry squad.
Boost for Newcastle?
Cole recently visited West Ham United's youth academy and he appears keen to help youngsters in the game wherever he can.
And that can only help Newcastle, whose young forward in Armstrong will not only now get both goals and game time at Coventry - but the help of a former England icon.
Cole's expertise both in games (if he plays) and in training will be just what 18-year-old Armstrong needs.
It's a great move for the Magpies, Coventry and Aston Villa, then, as Cole won't be rotting on the bench at Villa Park. Fair play to the veteran, who appeared genuine when claiming he wants to get minutes under his belt this season.