Jos Hooiveld could be out for the next few weeks after aggravating his injury but the return to full fitness of defenders Andreas Hinkel and Glenn Loovens will be a boost to Celtic. Hinkel insists that the Celts can score four every game but he knows the problems are at the other end of the pitch. Andreas Hinkel returns from injuryCeltic boss Tony Mowbray watched his side throw away two precious points in the last 15 minutes at Pittodrie on Saturday as Aberdeen came from 4-2 behind to snatch a share of the spoils. The late capitulation allowed the Huns to regain their 10 point lead at the top of the SPL table with 13 games left to play but the manager is still refusing to concede that the battle for the title is over. Mowbray has set his sights on six points from the next two matches - at home to Dundee Utd on Saturday and away to the Huns the following Sunday - to reignite Celtic's championship challenge and although some may think it looks like Mission Impossible, given Celtic's recent form, Andreas Hinkel agrees with his boss that it's not over whilst there are still 39 points up for grabs and he hopes to play his part in overturning the hefty points deficit."It's always hard to watch the games and not be able to do anything and, of course, it was another disappointment against Aberdeen," said Hinkel. "But this is not just a saying, this league is still not over. We have to believe that. Just now there is still a chance and we have to keep believing as things can change so quickly. It's very difficult, but you have to be positive. We are all realistic and see the gap is 10 points. What we have to do just now is win all our games first. What is important now is getting a result against Dundee United, take the three points and then we will see what happens week after week.""There are 13 games and 39 points to take." said the German international. "We just need to win, improve our confidence and hopefully we can catch up. I'm very happy to be back after two weeks of doing nothing. You can look forward and influence the game again. When you are a player, being injured is the most horrible time. If you have a muscle injury, the first few days especially are very boring because you can't do anything and you can only get treatment on machines. The second week is better, but it's not the same as training with the team, so because of that I'm very happy and pleased to be back.""I feel good as I didn't lose a lot of fitness since it was only under two weeks ago that I got injured." continued the right back. "For around the first three days I didn't do anything, but then I started on the bike and I did some runs. I also did gym sessions for the upper body, which is good as when you are injured you can do different things, so I was in the gym three days in a row doing that. So, I don't think I really lost any match fitness and may have got stronger."Celtic have found it extremely difficult against United recently. The Arabs drew 1-1 at Celtic Park earlier this season and then came from a goal behind to beat Celtic 2-1 at Tannadice in November so Hinkel realises that taking all three points from them will not be a formality. "I think it is always difficult when these teams play deep." he said. "In the first half against Hearts we had our chances, but it was difficult as there was no space. In the second half we scored two early goals and then we got the space and that allowed us to show how we can play and use our qualities."I think Dundee United will be the same." he continued. "They are very good at the back and are well organised and we have to play fast and keep the tempo high. If we don't score early, it's important we continue to keep them under pressure. Playing quick is the most important thing. We need to hold onto the ball and make simple, sharp passes and tire them out. If we try and force it too quickly sometimes then I think we lose the ball and that allows teams to counter attack. We need to wait for our chance and then make the right decision when it comes."Recent recruits Robbie Keane, Morten Rasmussen and Diomansy Kamara have all impressed and the right-back has no doubts about the quality options we now have up front, but he also recognises that we have been much weaker defensively. "We scored four goals last week and we can do that in every game. It is a good thing as we weren't taking our chances before. It takes time to gel, of course, but I think the guys who have come in are quality players. What we need to do is concentrate on the defence more and defend the goal with our lives. After that, hopefully, we can start on a good run."