Ousmane Diomande could provide Nottingham Forest with a huge future cash windfall.The Ivory Coast international completed a £34.3million switch to the City Ground on Tuesday in what could be a real coup for the Midlands club.Diomande could be Forest’s next jewell in the crownGettyThe centre-back, who spent four seasons in Portugal with Sporting Lisbon, was Forest boss Oliver Glasner’s defensive priority this summer.It has been an eventful summer of ins and outs at the club led by Elliot Anderson’s £116m switch to Manchester City.The England international initially joined the Tricky Trees from Newcastle in a £35m deal in 2024.Forest’s development of the midfielder saw them recoup a whopping £81million in fees and according to European football expert Andy Brassell, Diomande could earn the club a similar fee in the future.The 22-year old completes an impressive-looking back three alongside Nikola Milenkovic and Murillo and Brassell believes Anderson’s exit will not weigh too heavily on Glasner’s side.Brassell told talkSPORT.com: “I don’t see it as a massive departure for Forest because it’s not that dissimilar a signing really to Milenkovic because of course he was cheaper and he was a little bit older.“But I remember when Forest signed him (Milenkovic) I was like, ‘whoa, yeah, the Premier League does have real power’, because realistically, I could have seen Milenkovic going to, with all due respect to Forest and their history, a bigger club than Forest. “And ever since he arrived in the Premier League, I’ve said time and time again there is no more difficult position to adapt to the Premier League than as a defender; it’s hard.“It’s really hard because the game is super fast. It’s super physical. The referees let more go. “Teams are fighting for the right to counter-attack, and it’s just like, sort of I don’t know, crossing a six-lane highway in Texas as a pedestrian. Forest were the recipients of a cash windfall thanks for Anderson’s move to Man CityIsaac Parkin / Manchester City FCBrassell believes Diomande could quickly cement himself as a key player for Forest, much like fellow defender Milenkovic (right)Getty“We’ve seen some of the best defenders in Premier League history have really difficult starts to their time in the Premier League. I mean Patrice Evra is the most obvious one, I suppose off the top of my head, but Milenkovic adapted so smoothly.”Brassell believes Milenkovic’s trodden path could be replicated by the club’s latest arrival after impressing during a successful spell in the Portuguese capital.Brassell added: “I believe that Diomande can do that because he’s someone who’s become a really important player for Sporting over recent years. “Good signing; came with a reputation, but has been coached into someone who really is the real deal. “They were always gonna sell him this summer; they couldn’t hold on to him, and someone like him who’s big, can mix it and is tidy on the ball. I don’t know what more we could want really from a defender. “Now, again, we’ve seen with Forest, I suppose Elliot Anderson being the obvious example, they develop players into players that they can sell on for an absolute fortune and that can finance future rebuilds. Diomande featured once for his country at this summer’s World CupGetty“Now, maybe they’re not able to do that with Milenkovic.“Maybe they do it eventually with Murillo, but I think it’s fair to say there were more difficult sells than Elliot Anderson was. I don’t think Diomande will be a difficult sell.“If he comes into Forest and does as well as I expect him to do and he sells, and we’ve seen defensive players do really well at Forest before, as we said, name-checking those two in recent years. “If he does as well as I would expect him to do, they could sell him for a few times the amount they’ve paid for him in a year or two time I think.”After completing his move to the City Ground, Diomande vowed to give his all for the Forest cause this season.Diomande said: “I am very happy to be here. It is a historic club, and it motivates me to join such a club.Oliver Glasner is constructing one of the Premier League’s meanest defencesGetty“I believe we can achieve very good things this season and I am looking forward to meeting the players and head coach.“I will give my best and all I can to help the team. I cannot wait to meet the supporters at the City Ground and together we can have a good season.”