'We have one or two injuries but that is too easy an excuse for people to use,' Keane told MUTV.
'It is a great opportunity for players coming into the team to show what they can do and the team we put out on Sunday was capable of beating West Ham away.'
'I am doing really well and working hard, especially in the last three or four weeks,' he said.
'I would like to be helping out the team and doing my job on the pitch but I have to be patient.
'I don't want to set myself targets which might be unrealistic. I will just listen to the surgeon and hopefully be able to continue following the fitness programme I have been given. Once I'm ready to twist and turn it won't be long before I am back in the team.
'It is the first time anyone at the club has had this type of injury and maybe that's part of the reason why I put off surgery in the first place.
'But I am glad to have had it done and mentally and physically I feel good.'