More than 100 games into his Premier League career and there is still talk of Marcus Rashford’s potential.That might be a fair enough assessment considering his relatively tender age of 21 but the sums involved in the striker’s new contract are not usually reserved for players of potential. They are for the finished product.There is no question that there is a special player inside of Rashford, but he has not yet shown it consistently or often enough to justify United’s massive outlay at this stage of his career. But the club have – as usual over the past number of years – done business badly. Article continues below Editors’ Picks ‘Everyone legged it on to the pitch!’ – How Foden went from Man City superfan to future superstar Emery out of jail – for now – as brilliant Pepe papers over Arsenal’s cracks What is Manchester United’s ownership situation and how would Kevin Glazer’s sale of shares affect the club? Ox-rated! Dream night in Genk for Liverpool ace after injury nightmare They have been backed into a corner by Rashford’s hardball negotiation, as he is entitled to do. The clock had been ticking on Rashford’s previous deal.Having broken into the first-team picture under Louis van Gaal, Rashford signed a proper contract in the summer of 2016 just after Jose Mourinho was announced as manager. Various estimates have put that contract’s value at somewhere between £25,000 ($32,000) per week – excluding bonuses – and £80,000 ($100,000). Whatever happens from now on, the England forward is guaranteed a lot more than that from this day out.This won’t be an incremental rise in line with an already-existing pay structure. It would appear that Rashford held the aces right from the beginning of negotiations, with the summer 2020 deadline in sight.As the calendar moved closer to that date, Rashford held more power. That was the original expiration date on his contract even if United reserved the right to extend that deal until 2021.That extra year option is included in most United contracts these days and gives the club a little wriggle room if time is running out, players are stalling and no agreement is in sight. Extend terms and have a bit more breathing space when it comes to selling the player in the market.That would have been the situation in 12 months’ time, with Rashford a year away from walking away from Old Trafford for free and into the welcoming embrace of a team of a higher stature.Real Madrid, Barcelona and Manchester City are all credited with interest in the United academy graduate and losing him for nothing would have been a terrible blow for the club and not least executive vice chair Ed Woodward.Without a technical director in place, contract extensions belong in a grey area around Old Trafford, with news a few months back revealing that nobody had been in touch about renewing terms with Ander Herrera, who as of today is a free agent and expected to sign for Paris Saint-Germain.No such problem with Rashford although the terms discussed – around £200,000 ($250,000) per week but potentially rising above £250,000 ($316,000) depending on bonuses – mean United have paid a premium to get it done.And that is one of the unintended consequences of the Alexis Sanchez deal. Jose Mourinho was hell-bent on blowing Manchester City out of the water for the Arsenal forward in the winter of January 2018 and that has created a legion of problems at the club.When other players are aware of the terms of Sanchez’s contract – some £25 million ($32m) per season if all bonuses and clauses are met – representatives are entitled to ask questions when it comes to their own clients’ renewals.Rashford has performed far better than Sanchez during their time together. He is younger and worth more than the Chilean in the transfer market. By most metrics, he is a more valuable player but United’s structure-busting deal means he was being paid far less than Alexis. ‘If he’s worth x, then my guy is worth y,’ is a very simple way of putting it. And United really had no comeback.It is a day for celebration, there’s no question about that. Rashford did not cost anything in the way of a transfer fee and has many successful years of football ahead of him. United have tied down a player who would possibly have been the most sought-after free agent in football history if his contract expired.The recent NBA free agent frenzy demonstrated clearly that the players hold the power when it comes to that kind of negotiation. Football is no different. But Rashford remains under contract at United; he would be an asset for any team and now needs the right environment to thrive.He has been around the first-team picture at United for less than five years but has already worked under three vastly different managers. The long-term future of the third – Ole Gunnar Solskjaer – will be by no means secure if United again fail to hit their marks this season.Rashford scored only two league goals between the middle of January and the end of the season. While others like Romelu Lukaku and Paul Pogba were getting it in the neck, Rashford was spared the scrutiny.But that changed at the conclusion of the campaign, when Rashford came in for criticism due primarily to his proximity to fan punch-bag Jesse Lingard. There were demands for a higher output and more consistency.Those calls will only increase now that he is being paid sums more suited to Champions League and World Cup winners, rather than FA Cup and Europa League winners.United’s big wage errors with Alexis led them down this path, paying mammoth salaries to players without the background to merit them but nonetheless with sufficient leverage to ask for it.What they need now is the payoff, namely consistent performances, plenty of goals, and a clear path to fulfilling that potential. Because, for that money, you’d expect more. Check out Goal’s Premier League 2019-20 fantasy football podcast for game tips, debate and rivalries.