Roy Keane believes Manchester United "still need one or two into the group to really challenge", with the former Red Devils captain seeing Ole Gunnar Solskjaer's side sitting behind arch-rivals Manchester City and Champions League winners Chelsea.
Pep Guardiola and Thomas Tuchel have been given funds to strengthen with this summer, with a £100 million ($139m) deal at the Etihad Stadium seeing Jack Grealish break the British transfer record, while Romelu Lukaku may be heading back to Stamford Bridge for £98m ($136m).
United have also invested, with £73m ($101m) spent on Jadon Sancho and £34m ($47m) on Raphael Varane, but Keane believes more is required in order for the most prestigious of honours to be landed at Old Trafford.
What has been said?
Reflecting on recent recruitment business with ITV Sport, ex-United midfielder Keane has said: "Two very good signings, particularly Varane with his experience with the problem at the back.
"Sancho, a young talented player who did well in Germany.
"I still think what City have done and Chelsea with Lukaku, United still need one or two into the group to really challenge."
Who have Man Utd been linked with?
There is plenty of speculation to suggest that Solskjaer remains in the market for further additions in the current window.
A new right-back is said to be a top priority, with Atletico Madrid star Kieran Trippier generating plenty of rumours as the England international sees a return to his homeland mooted.
There has also been talk of another centre-half being brought in, with the Red Devils among those to have been linked with Sevilla defender Jules Kounde and Villarreal ace Pau Torres.
Possible additions in midfield are also sparking plenty of gossip, amid questions of Paul Pogba's future, with Rennes starlet Eduardo Camavinga and Lille playmaker Renato Sanches said to be registering on the Red Devils' radar.
Clubs in England have until August 31 to get any business done, with United determined to put themselves in a position where a five-year wait for major silverware can be brought to a close in 2022.