"We played some good football at times and had good control of the game".
The last switch yielded reward nearly immediately when, with 15 minutes left, French-Moroccan striker Faissal El Bakhtaoui ran straight at the heart of the Celtic back line and uncorked a 25-yard drive which lanced beyond Craig Gordon.
The Celtic star claimed his 12th goal of the season as the Parkhead side moved to within three points of sixth consecutive title with a 2-1 win in Dundee.
Now Armstrong is hoping a season where he has already scored 12 goals can continue to prove memorable by him winning a first global cap, with Scotland due to face Canada on Wednesday and then Slovenia on Sunday.
The 24-year-old's fine performances this term have seen him recognised by the Scotland worldwide team.
Dundee Paul Hartley watched his side lose out to Celtic by a single goal for the third successive game following a 1-0 defeat at Dens and a 2-1 loss at Celtic Park earlier in the season.
"The one thing I will say is that I have always believed that global football is about technique, speed, mobility and a tactical awareness, and he has got those elements".
Rodgers said: "It would be a good to win it at Tynecastle".
"He's a big talent and he's only going one way, which is nice for Celtic and for Scotland", said Rodgers. And those elements of the game he has.
"We have nine games left in the league. So he could certainly go in and play".
Singling out Armstrong's display, Rodgers added: 'I thought he was outstanding again.
"We have a couple of weeks and I hope they all come back from worldwide duty fine", he added. So this is our next one.
"If we make the top six then great, and if not we need to make sure we are safe for next season". "The ideal scenario would be you win it yourself but I will take Dundee winning it".
The Glasgow giants were put on the back foot as Dundee pressed for an equaliser and were forced to take off winger Scott Sinclair and bring on centre-half Erik Sviatchenko to help defend their lead.