Middlesbrough chairman Steve Gibson insists the club will be competitive on its return to the Premier League having learned from past mistakes.
Gibson revealed Boro have learned from previous errors when it comes to transfer dealings, admitting he should never have sold Lee Cattermole.
The Sunderland skipper came through the academy at Boro before making his professional debut with the club in 2005.
But after 69 appearances for the Teessiders, he was sold to Wigan Athletic for £3.5million in the summer of 2008 - and Gibson admits Boro lost him at the "wrong time".
The tough-tackling midfielder joined the Black Cats in 2009 from Wigan Athletic for £6million and the 28-year-old, a former England Under-21 international, hasn't looked back since, signing a new five-year deal last summer to commit his future to the club until 2021.
Gibson admits Stockon-born Cattermole was one that got away, with Boro learning sharp lessons in the transfer market over the years.
"When I look back at the last time we were in the Premier League we got some things wrong," said Gibson at the recent Premier League Coaches Conference.
"We got our recruitment wrong and we let some players go that shouldn’t have gone and replaced them at greater cost but with lesser players.
“We lost Lee Cattermole at the wrong time.
"Lee was quite a character and needed to be managed quite strongly and I wish we never let Lee go, and one or two others we perhaps shouldn’t have let go at that time.
"Our recruitment wasn’t as good as it could have been and I think we have addressed that, but it’s still difficult to get the right players.
"You’re asking a lot of a player to pick up and move his family to new faces in a dressing room, different coaching methods different fitness methods and it doesn’t always work.
"Sometimes a player can be at a club that’s made for him, but he doesn’t know that until he’s gone and we’ve had one or two players who were better for us, and you have players who have left us and were better where they’ve gone."
Gibson is adamant his Boro side, under the guidance of head coach Aitor Karanka, will be a force to reckon with on their return to the top flight after a seven-year spell in the Championship.
He added: "A lot of the work has been done in terms of recruitment for next season and thankfully we can press ahead with plan A.
"We know our targets and we can start that process.
"Can we compete again? Yeah we have some very exciting youngsters, Ben, Ben Gibson, is a really exciting prospect for the Premier League. Is he up to it? He tells me he is, we will know by this time next year.
"We are a club with no debt, we own the stadium and we own the training ground.
"We’ll have to make some investment in the stadium, a lot has changed in the seven years we have been out of the Premier League.
"So there will be a small investment in that, but other than that every penny we’ve got will be to improve the squad."