Manchester United are not ready yet to become the dominant force in English football they were during the trophy-laden years of the Alex Ferguson era, manager Jose Mourinho has said. United have finished seventh, fourth and fifth in the Premier League since the retirement of Ferguson, who led the club to 13 Premier League titles, two Champions League trophies and five FA Cups in almost 27 years at Old Trafford. Mourinho, who has already won the League Cup in his first season in charge, believes the club is still far from ready to compete for major trophies on a consistent basis. "We are not ready to be a dominant force. We are not ready to try and win everything," the Portuguese, the club's third permanent manager since Ferguson stood down, told the BBC. "Because of the nature of the club, and of myself, we are ready to fight for every game, every point. "But there is a space between the general ambition of such a giant club and what we are in reality." Mourinho, who won three league titles in two spells with Chelsea, also questioned the club's transfer business under his predecessor Louis van Gaal, who sold strikers Danny Welbeck and Javier Hernandez as well as winger Angel Di Maria. "I would never have sold Di Maria, Chicharito (Hernandez), Danny Welbeck -- never, no chance," Mourinho added. "I found a sad club. Manchester United sold players that I would never sell, bought players that I would never buy." Mourinho signed Zlatan Ibrahimovic, Paul Pogba, Henrikh Mkhitaryan and Eric Bailly at the start of the season and allowed midfielders Memphis Depay and Morgan Schneiderlin to leave the club in January. United beat Russian side Rostov 1-0 on Thursday to reach the last-eight of the Europa League and are sixth in the Premier League with 12 games to play.