Lisandro Martinez 'challenged' by team-mate on flight home as Man Utd plot next steps

One Manchester United player is understood to have challenged team-mate Lisandro Martinez on their flight home from Madrid following his explosive comments in a post-match interview . United defender Martinez slammed the higher-ups at Old Trafford for not signing enough players in the summer transfer window , leaving the team ill prepared for the Champions League . The 28-year-old even took aim at director of football Jason Wilcox , saying that he 'expects more' from him. His comments came after Michael Carrick's team suffered a controversial 2-0 loss against Atletico Madrid .