Manchester United's search for reinforcements at left-back this summer ultimately fell short after Newcastle United refused to sanction the sale of academy graduate Lewis Hall, according to reports. Michael Carrick reportedly identified strengthening the left-back position as a priority during the transfer window, aiming to provide competition and support for the club's long-serving Luke Shaw following United's return to Champions League football. Several names were reportedly considered before Hall became the frontrunner, including Barcelona's Alejandro Balde, Arsenal's Myles Lewis-Skelly and Fulham's Antonee Robinson. However, Newcastle stood firm on their valuation of the England youth international, even amid suggestions that a bid in the region of £75million could have tested their resolve. The Magpies had already seen key figures Anthony Gordon, Sandro Tonali and captain Bruno Guimaraes depart in previous windows, and were unwilling to lose another prized asset. Former United defender Wes Brown believes the club made a mistake in not pursuing Hall more aggressively. "You can see Lewis Hall is the real deal," Brown told Oddschecker. "He's young and he's definitely a player you could bring into United who would fit in really well. So, I would have definitely paid the fee for him. He would be a great fit. Luke is still a tremendous player but there's always that question mark over his injury record." With the Hall deal falling through, United's issues at left-back were compounded by an unsuccessful late approach for Manchester City's Rayan Ait-Nouri. That failed pursuit means Diogo Dalot remains the only genuine backup option for Shaw heading into the new season, raising concerns about squad depth in that area. Hall was not the only target Brown feels United should have pushed harder for. The former defender also expressed regret over United's inability to land Real Madrid midfielder Aurelien Tchouameni. "Tchouameni is an excellent player, lots of experience," Brown said. "His performances have been up and down at Real Madrid, but at the same time, I think he would have been excellent at Manchester United. He covers the pitch well and has great quality. He's played in all the big games but again, it would have all come down to the price." Reports indicate that wage demands proved to be the sticking point in any potential deal for the France international. Instead of pursuing Tchouameni, Carrick's side turned their attention to Brighton's Carlos Baleba, completing a deal for the Cameroon international worth up to £70million. Brown also highlighted Crystal Palace midfielder Adam Wharton as another player he felt United should have targeted this summer, praising his all-around qualities. "I still think he's a player with great quality," Brown explained. "He gets the ball, he can pass forward. He can tackle, he's young and if you can get him at the right price, I think he would have been a brilliant buy." With the transfer window now closed, United fans may be left wondering what could have been, particularly given the uncertainty surrounding their left-back options heading into a crucial Champions League campaign. Whether the club revisits interest in Hall, Tchouameni or Wharton in future windows remains to be seen, but for now, Carrick will have to work with the squad assembled, including the summer arrival of Baleba as a marquee midfield addition. Based on reporting from standard-football.