Roberto Martinez says he is disappointed that he was not given the chance to continue his work at Everton ahead of a "significantly important" summer transfer window.
Martinez's three-year reign as Everton boss was brought to end on Thursday following a disappointing Premier League campaign.
The 3-0 loss to Sunderland on Wednesday stretched the Toffees' dismal run of form to just one win in 10 matches in all competitions and proved to be Martinez's final game in charge.
Martinez, who led Everton to the semi-finals of the FA Cup and Capital One Cup this season, acknowledged recent results had not been up to scratch and also expressed his thanks to chairman Bill Kenwright.
"It has been an honour to be the manager of Everton Football Club for the past three seasons. I am clearly disappointed that we won't be able to finish what we started and I feel that the forthcoming transfer window would have been significantly important for many reasons," Martinez said in a statement released via the League Managers Association.
Billionaire Farhad Moshiri purchased a majority 49.9 per cent stake in Everton in March and promised to give the club all he can during his time in charge.
Martinez continued: "I will treasure this period as Everton manager forever - the memories of reaching a club record 72 points tally in the Premier League, reaching the final 16 of the Europa League and the excitement of reaching the semi-finals of both domestic cups this season.
"I express my gratitude to chairman Bill Kenwright, who understood and supported my vision and who gave me the privilege of becoming an Evertonian.
"My sincere thanks also go to my players who have been an inspiration to work with, my assistant Graeme Jones, the Everton Board and all of the staff who work for this magnificent club, especially those at Everton's Finch Farm training ground for their tireless help and support on a daily basis.
"I appreciate that over the last eight weeks our league results haven't been up to the levels that we would expect. However, over the past three years the support the fans have given to me and the team has been inspiring.
"I know that the team and the fans will react well against Norwich today and I wish everyone the best of luck for three points which would match last season's league points tally."
Martinez also took the time to wish veteran goalkeeper Tim Howard well as he prepares to leave Everton for Colorado Rapids.
Howard, who joined Everton in 2006 and has since played over 400 times for the club, will depart following the final match of the season against Norwich on Sunday.
Martinez added: "I would like to congratulate Tim Howard on his outstanding contribution and career at the club. Tim has been an incredible ambassador for Everton and I wish him well for his future in the MLS."