Manchester United were linked strongly with Arturo Vidal all summer, settling for Ajax man Daley Blind to complement Ander Herrera in midfield.
Their deadline day activity ended with the spectacular signing of Radamel Falcao on loan, but questions remain over the depth in the middle of the pitch.
One option is to scour the free agent market for players to sign outside of the transfer window, although there are slim pickings for a club with standards as high as Manchester United.
There is one player who stands out however, and that is a former international teammate of Arturo Vidal, the player they desperately wanted, in Chilean midfielder Marco Estrada.
Estrada, 31, has 33 caps for Chile, scoring once, and has been a free agent over the course of the summer.
Until last season he was playing an important role for French side Montpellier, where he scored eight goals and provided 12 assists during 84 Ligue 1 games.
A defensive midfielder, Estrada still contributed a goal almost every four games, an impressive ratio by anybody's standards.
His career has stalled after electing to move to the Middle East to play with UAE side Al Wahda, and having his contract cancelled by mutual consent after 10 matches, during which he scored twice.
Part of Montpellier's 2011/12 Ligue 1 title winning side along with Olivier Giroud and Younes Belhanda, it was only two seasons ago he was playing Champions League football, featuring against Arsenal, Olympiakos and Schalke.
An expert from set pieces, Estrada has an eye for the spectacular, and averaged over two shots per game during his final season at Montpellier, two tackles per game, and 2.4 interceptions.
At 31 he still has enough to offer in terms of a short-term squad role, and could be an intriguing late addition to the Red Devils, if Louis van Gaal is prepared to get creative in terms of strengthening the midfield.