When Celtic signed Stuart Armstrong in a deal worth around £1.75m back in February of 2015, few would have expected the central midfielder to be playing his football in the Premier League just three and a half years later.

However, after scoring a highly impressive 28 goals and registering 25 assists over his winning four Premiership titles, two Scottish Cups and two Scottish League Cups, this is exactly what Armstrong was doing - with Southampton paying Celtic £7m for the 29-year-old's services back in the summer of 2018.

Since then, the Scotland international has turned into something of a stalwart in the Saints midfield, making 122 appearances over his three and a half year spell with the South Coast side, as well as turning in a consistently impressive level of performance in this time.

Indeed, over his 29 Premier League appearances in 2018/19, the £12.5m-rated man earned a seasonal SofaScore match rating of 6.71, over his 30 league outings in 2019/20 he earned a seasonal match rating of 6.73 and over his 33 top-flight fixtures last term he earned a seasonal match rating of 6.76.

It has been a very similar story for the £58k-per-week midfielder over his 14 Premier League games so far this season, with the 29-year-old having made an average of 1.1 key passes, taken 1.9 shots, made 0.5 interceptions, 0.6 tackles and won 2.6 duels per game - with these returns seeing the player who Ralph Hasenhuttl dubbed a "role model" average a SofaScore match rating of 6.72.

As such, while £7m is certainly not a figure to be sniffed at, considering the fact that Armstrong has been an extremely consistent performer for a mid-table Premier League side for the best part of four years, it is easy to see why the Saints manager dubbed the midfielder's transfer fee "cheap."

Indeed, should Celtic have held onto the Scot a little while longer, they could well have demanded a much higher figure in order to part with the 29-year-old, something that the club will undoubtedly be regretting.

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