The energetic left-back, who has been at The Pilot Field since autumn 2011, has been released following a dispute between himself and the football club.
Whitehead was angry that United were unwilling to pay for a scan on an injury he sustained last week, with his main gripe being that another player had a scan paid for earlier in the season.
He wrote on social network site Twitter: “How can a football club refuse to help one of their players get treatment for an injury when they have already treated others in the team.
“One person had his scan paid for and till this day with his injury is still being paid and another player offered treatment then refuse me. And the excuse is that they were exceptions, deeming me as unimportant as a player of their club!
“Then also not paying players’ expenses to get to games and having to pay out of your own wages to get there! To top it off we have been given minimal bonuses after what we did for the club and had to pay for our own drink at a club meal.
“Would like to thank all the fans and all of those who worked tirelessly and gave their own hard work and dedication to me and the club.
“You are absolutely incredible to play for, the year I achieved at the club will never be forgotten, such as reaching the FA Cup 3rd round.
“Those who work behind the scenes endlessly without being noticed such as Simon Rudkins and Pat McCrossan, and all stewards and bar staff.
“And of course all my team-mates who made everything so memorable! I am very sad to leave the club on these terms but the situation has become unattainable due to the treatment towards me. Once again I applaud all fans and staff for everything. Great people and club.”
The club released the following statement on its website yesterday evening: “It is regrettable to announce that defender Matt Whitehead has been released following a disagreement between the club and the player.
“Matt had asked the club to pay for a scan in order to assess the injury that he suffered during the Sussex Senior Cup tie at Peacehaven & Telscombe last Wednesday.
“However, the policy has always been that the club does not pay medical bills on behalf of players, unless there are exceptional circumstances, and players are made fully aware of this fact when they sign for the club.
“It is generally unrealistic for non-league clubs to fund private medical treatment for players as it is simply too expensive. It is something that the club has done on only one occasion during the last nine years, when the circumstances were truly exceptional.
“Prior to the U’s televised home FA Cup second round replay against Harrogate Town, the club was facing the distinct possibility of going into the biggest game in its history without a specialist goalkeeper.
“Matt Armstrong-Ford had suffered a serious knee injury during the early stages of the first game in North Yorkshire, while his understudy Joe Winchester then broke a thumb in the League Cup tie at Worthing four days later.
“FA rules prevented United from signing a stand-in keeper for the replay, but there was still considerable debate within the club about Matt Armstrong-Ford’s fitness.
“Matt wanted to play in the game, but was naturally worried about the longer term implications for him if he aggravated his injury.
“The club therefore decided that, in an effort to try and put Matt’s mind at rest to as great an extent as possible, it would pay for a scan to assess the damage to his knee and, in addition, that it would also continue to pay his wages if he was subsequently unable to play for a period of time.
“Neither of these things would typically be offered to a non-contract player, but as a result, Matt duly took his place in goal and helped United through to the third round.
“After the club had declined Matt Whitehead’s request to pay for a similar scan, Matt confronted chairman Dave Walters about the situation and was unwilling to accept the explanation outlined above.
“His response was unacceptable and his disrespectful attitude was such that the club had no option, but to advise him that he no longer had a future at The Pilot Field.
“Furthermore, the club is aware of certain comments that Matt has subsequently made on a social media wesbite with respect to the payments of bonuses and travel expenses, and would like to state for the record that these statements are simply not true.
“Situations like this are never pleasant, of course, and this development has been anything other than helpful given the U’s currently worrying run of league form.
“For a number of years, the club has had very little money to work with, but has remained solvent, made a certain amount of progress and retained its Premier Division status regardless.
“The fact that financial concerns have now eased somewhat has brought with it a completely different set of problems, but the club will continue to adopt the same prudent approach that has kept it solvent and will look to invest in ways to safeguard its future both on and off the pitch.
“The management team and the directors are committed to doing their best for the club and genuinely appreciate the continued support of supporters in achieving this mutual aim.”