The 25-year-old midfielder scored three times for the Parkhead side and made his Scotland debut in the 1-0 World Cup qualifying win over Slovenia at Hampden Park.
Armstrong started April by scoring in the 5-0 win over Hearts at Tynecastle which clinched the Hoops’ sixth successive title.
He said: “It has been a very good month, with the Scotland experience and the league.
“I haven’t had a chance to think about it too much.
“The season is still ongoing and we are still focused on finishing the league strongly, but when the season is over I will look back and I am sure there will be some highlights.
“Awards are always nice to receive but I think there are more important accolades for the team, and to get the league and (Betfred) Cup has been great success for us so far.”