The 18-year-old Newcastle United striker kicked off his loam spell with the League One side with five goals in his opening three outings this season before netting just once in his next five appearances.
But Armstrong was back at it again on the weekend, firing home a match-winning brace for the Sky Blues in their 3-0 home win over Shrewsbury Town.
The opening goal came in the 26th minute courtesy of a well-placed effort from range after receiving a pass from Marc-Antoine Fortune before the Frenchman converted from the penalty spot in stoppage time of the first half.
Armstrong then essentially wrapped up proceedings with 25 minutes remaining when he raced onto another ball from Fortune to rocket beyond Shrews keeper Mark Halstead from just inside the area, before producing a merry jig.
Check out Armstrong's goals below. The first from the beginning and the second from 1:38:
A hat-trick was on the cards for the England U19 international but a looping right-footed effort from distance had a little too much on it to find its way under the crossbar.
In the wake of another sublime performance, Coventry boss Tony Mowbray spoke of Newcastle boss Steve McClaren's potential desire to have Armstrong back at St James' Park given the Magpies' horrific start to the Premier League season.
“I had a good long chat with Steve last week. He wants to know how he's (Armstrong's) doing and he wants to know how we're playing him," Mowbray told Coventry's official website.
“He's not just stood up front between the two centre-halves, he's developing his game.
“He's a part of the team and the way we function, and we've played him behind the main striker and on the wings which is important for him.
“It's important that if he wants to play in the Premier League that he develops his football knowledge.
“With total respect to this league, he won't be sprinting away from Premier League centre-halves like he does at this level.
“Regarding his future, we've just got to let the boy enjoy his football.
“He's very respectful of the group and I really enjoy working with him as he is very humble, and just because he's scored a few goals doesn't mean that he wants to stop learning."
Armstrong, who landed a spot in the Football League Team of the Week for his efforts, now has eight goals in nine appearances for the fifth-placed Sky Blues which has him sitting on top of the League One scoring charts.
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