Brendan Rodgers’ Celtic side cruised past Astana 5-0 in the Champions League last night.
Armstrong was one of Celtic’s key players last term, but he has seen his place come under threat following the arrival of Olivier Ntcham from Manchester City this summer.
And it was Ntcham who was favoured over Armstrong against Astana last night.

Armstrong could hardly have any complaints about the decision, given the dominant nature of Celtic’s 5-0 victory.
And Rodgers claims it was not a difficult decision to leave the former Dundee United man out of his line-up.
“It was quite easy,” Rodgers said, when asked if it was difficult to leave Armstrong out of his line-up.
“At this level, at this stage, Ntcham came in because of his ability to control the ball. Stuart’s a goalscoring midfielder, but we decided to play with two controllers with Ntcham and Browny. I thought that was the right call, and I thought he was fantastic.”
Armstrong’s contract situation at Celtic appears to have distracted the midfielder.
The Scottish international’s performances have dipped slightly this term, as he only has 12 months remaining on his deal.
Celtic are expected to agree a deal with Armstrong in the near future though, according to BBC Sport, which should put to the rumours over his future to bed.

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