Fox wants U's to start climb up table.
Recent performances in league and cup have probably merited better results than they've garnered, but the experienced midfielder wants his teammates to get results in the coming matches - by whatever means necessary.
Speaking after extending his contract on Thursday afternoon, he said: "The last three or four performances have been good, but we're at the stage of the season now where results are all that matter.
"At times, we're going to have to grind it out and win ugly and it might have to be that it's a backs to the wall job to get the result, but results are the key thing now.
"That said, good performances will also give us the best possible chance of getting those results.
"We know we've got players, especially at the top end of the pitch, who can win us games. There have been positives in recent games, but now we need to build on that."
The U's were knocked out of the FA Cup at Cardiff last week and, prior to that, had put in good displays against Gillingham and Crawley.
However, looking back at those games, David added: "We've got beaten by three set pieces against Cardiff and it's the fine margins that we have to get locked down.
"We're not quite getting those finer details right and we have to do that as an eleven to make sure we can make the most of the chances at the other end of the pitch."
The U's go to Peterborough on Saturday, with the Posh looking for their first home win in six league games.