Celtic are currently in a tough spot as they prepare to watch bitter neighbours Rangers shatter their hopes of lifting their tenth consecutive Scottish Premiership title.

Not only are they struggling with form, but they risk losing a lot of their key players either this transfer window or in the summer. Odsonne Edouard is one man linked to a potential Arsenal move, whilst interest also ramps up around centre-back Kristoffer Ajer.

They have also now confirmed the departure of 20-year-old Jeremie Frimpong. The right-back has made a permanent move to Bayer Leverkusen, as reported by the club's official Twitter. The Scottish Sun claims that the move could reach up to a handsome £11.5million.

Whilst this is an impressive profit on the £350,000 they initially paid for him, sometimes the player is worth more to a club than his price tag.

Indeed, Frimpong had rapidly established himself as a reliable first team performer under Neil Lennon, but the manager confirmed he would be leaving Parkhead. The Dutch youth international recently posted a cryptic message on his Instagram, seemingly highlighting his unhappiness.

For Celtic to have made Frimpong feel as though his 'demands haven't been met', the defender must have been looking for a more advanced contract or stability in knowing he in untouchable in the starting eleven.

Frimpong has featured in every single Premiership match so far this season and has missed just two Celtic fixtures across the entire campaign, as per Transfermarkt. This is an impressive growth spurt for such a young player and no doubt Celtic's struggles this season will have disappointed him.

But the Bhoys are truly foolish to let him leave. At just 20, Frimpong has become a strong presence in the Celtic lineup and was Lennon's youngest option on the right side. Celtic have Anthony Ralston and Manny Perez as their other options, but the latter has just returned from loan and has just 18 months left on his contract.

Ralston is yet to establish himself as someone Lennon can rely on, having made only 20 senior appearances overall for Celtic and just the one this one season. Unless Nick Hammond can recruit a ready-made replacement, they will seriously struggle in the absence of "outstanding talent" Frimpong and will be forced to throw Ralston in at the deep end.

In other news, Lennon has sealed his own Celtic fate by not bolstering his squad...