Left for £2.2m, soared to £13.5m: NUFC had howler over colossus who was "world-class" - opinion

Newcastle United have had a number of successful players come through from their youth team to catch the eye in the first-team over the years.

The likes of Paul Gascoigne, Andy Carroll, Shola Ameobi and Steve Howey are just a few of the many who have made their way through the set-up, but it does not always work out for talented players and they sometimes have to make a name for themselves elsewhere.

One academy player the club had a howler with was goalkeeper Fraser Forster as they sold him at the wrong time in his career.

He came up through the youth ranks at St. James’ Park and did not make a single appearance for the senior side before he was sold to Celtic in 2012 for a fee of £2.2m in 2012 – via Transfermarkt.

The 6 foot 6 colossus spent three seasons out on loan before putting pen to paper on a permanent deal with the Hoops, playing one campaign with Norwich in League One and two with the Scottish giants – keeping a whopping 61 league clean sheets in that time.

Despite his impressive form for the Canaries and Celtic, Newcastle opted to cash in on him for a relatively small fee and they will surely be looking back on that with regret after watching what he achieved after leaving.

After catching the eye in Scotland, Southampton snapped him up in 2014 and gave him the opportunity to show what he can do in the Premier League.

To date, he has kept 54 clean sheets in 154 matches for the club, including 42 in 127 league outings. In the 2015/16 campaign, he set a Saints record as he went 706 minutes – almost 12 hours – of top-flight football without conceding a single goal.

In that season, Transfermarkt valued Forster at a whopping £13.5m – the pinnacle of his career according to their metrics. He held that value until