United will make a fresh bid for Everton left-back Leighton Baines in January, although David Moyes has publicly played down expectations of securing a high-profile signing in the upcoming transfer window.
"We have a fantastic squad as it is,” Neville told the BBC's 'Football Focus'.
“In the transfer window early on in the season we were looking for players, that was well documented.
"That search continues. We need to keep reinvesting in the squad because if you stand still in this league you get left behind, as Manchester City found out last season when they didn't strengthen as much and they ended up losing the league [title]."
Neville has praised Wayne Rooney’s performances this season and says the England international, paired alongside Robin van Persie, will keep United in the title race this term.
"His level of performance not just in games but in training has been first class," Neville said.
"And at the start of the season when we weren't in the best of form, he was a shining light
