Shaqiri has only played 40 minutes of football for Liverpool across all competitions since January.
He has been an unused substitute in the Reds' last four games, prompting debate over why he has suddenly fallen out of favour under manager Jurgen Klopp.
The Switzerland international looked like one of the bargains of the season earlier in the campaign, having been signed for only £13 million from Stoke City after their relegation [The Telegraph].
And former Liverpool right-back Johnson, who played alongside Shaqiri on the Potteries, believes that his former team-mate has probably already made his frustration known.
“When things were going well, he’d be a big player for us [at Stoke] and he’d perform. When things weren’t going well, he’d be hit and miss. That was obvious to see," he told BBC Radio 5 Live.
When asked whether Shaqiri would have ‘had a strop’ because he wasn’t getting game-time, Johnson added: “Most likely. Jurgen won’t deal with it – he’ll put it to bed.”
Wednesday's Champions League win over Bayern will have hurt Shaqiri.
He flopped at the Allianz Arena and he'd have loved to prove a point to his old employers, but Klopp kept him on the bench for the entire game as Liverpool marched into the quarter-final.
Klopp's side visit Fulham tomorrow and time will tell whether Shaqiri - who has six goals in 11 Premier League starts - makes his first appearance of the month.