Fulham manager Marco Silva has staunchly defended his heavily rotated squad following a shocking 1-0 FA Cup fifth-round defeat to Championship side Southampton. Despite making nine changes to his starting eleven, the Portuguese tactician refused to use a controversial disallowed goal as an excuse, instead pointing to his team's overall poor performance and demanding better execution.A highly intriguing FA Cup tie appeared destined for a draining extra-time period before a massive upset occurred. Fulham suffered a humiliating 1-0 defeat at Craven Cottage against Southampton, who currently compete in the Championship.The dramatic twist unfolded in the pivotal 90th minute. Southampton midfielder Finn Azaz smartly held his attacking run to stay perfectly onside before being clumsily brought down inside the penalty area by the trailing boot of Fulham defender Joachim Andersen. Striker Ross Stewart confidently stepped up to take the resulting penalty spot and hammered a powerful, low strike past goalkeeper Benjamin Lecomte, sparking delirious celebrations among the away supporters.Facing a congested fixture list, Silva opted to make nine significant changes from the team that recently lost to West Ham in the Premier League. Defending his rotation, he stated: "When you make nine changes – it was my decision, I’m going to get it. I’m the manager. We play Sunday – Wednesday – Sunday. If we say these players are not good enough to win a cup tie, we have to look in a different way." He also refused to blame a controversial disallowed first-half goal for the exit, insisting, "I don’t go in that direction. To talk about that moment is for me to find excuses."For Silva and Fulham, the late heartbreak cemented a deeply frustrating afternoon. The manager openly admitted that their overall execution simply fell drastically short of expectations and lacked the necessary clinical edge. He was left to accept the intense external criticism for his sweeping lineup changes while internally demanding a serious re-evaluation of his squad's overall fighting spirit and ability to deliver under pressure.On the opposite side of the Craven Cottage dugout, Southampton head coach Tonda Eckert was left ecstatic after securing a monumental victory. The ambitious manager immediately challenged his triumphant players to maintain their momentum and strive towards a return to Wembley. "It’s important if you get that little bit of a taste how it feels to win football games, you just stay on the gas and keep going," Eckert urged.Eckert also highlighted the deep historical significance of their current cup run, noting the Saints are wearing special commemorative shirts to mark the 50th anniversary of their 1976 FA Cup final victory. Praising the massive away support, he added: "You see how much it means to the club. It’s been 50 years since we won it for the last time. When we arrive on the coach and you look and the whole street is full of Southampton supporters, you can definitely say we feel the importance of it."Add GOAL.com as a preferred source on Google to see more of our reportingFor Fulham, the focus must now return to their league campaign as a promising season takes a significant hit. Silva acknowledged the scale of the disappointment and the work required to prevent a slump in form following such a high-profile cup upset."It's our obligation, we have to understand it was a very, very bad afternoon. We know anything can happen on football field, but it's more than that. We have to look deeper because it was not good enough and that starts with me looking at myself," Silva concluded, as he looks to find answers before his side's next Premier League game away at Nottingham Forest.