Scans have revealed bleeding in his groin area and our influential midfielder has been ordered to rest since the problem arose at Derby County earlier this month.
He admits Saturday’s Premiership derby at Arsenal might ‘be a bit soon’ but he is determined to play a part at Old Trafford.
Tim revealed: “Playing the Derby game I got a pain in my hamstring that I thought was a hamstring pull.
“I’d never had one of those before and I was a bit uncertain so I rested during the week leading up to the West Ham game and had a precautionary scan and there was a lot of bleeding in the groin area.
“It would have been too much of a risk to test it against West Ham so I had a little rest, rehabilitation and treatment with the physios and hopefully it won’t be long before I’m fit.
“I want to get back as quickly as possible but until I start training fully there is no guarantee that it has completely cleared up.
“Hopefully I can join in with training in the later part of this week and see how it goes. There are no guarantees but fingers crossed I’ll be back pretty soon.”
Despite the lure of the semi-final at Old Trafford, Tim insists he will not play unless he is fully fit.
He added: “You have to make sure you are ready. There is no point in playing if you are not fit enough because you’ll let the team down.
“If I’m fit enough I want to play and I will know between now and the game whether or not I am. I am not going to kid myself or anyone else that I am fit. If I’m fit enough I will want to play.
“The next two games are massive games. It might be a bit soon for Saturday but you never know.”
Tim Sherwood is fighting to be fit for the FA Cup semi-final against Arsenal next week.