Usain Bolt still the best despite Rome defeat, says Colin Jackson

Triple Olympic champion Usain Bolt returns to the track on Thursday following his 100m Diamond League defeat in Rome last week. Former 110m hurdles world record holder Colin Jackson discusses why the Jamaican lost to Justin Gatlin and analyses Bolt's chances of success in the 200m in Oslo and the World Championships in Moscow. The BBC Sport expert also assesses Jessica Ennis-Hill's injury and the potential of Perri Shakes-Drayton.

Everyone is always shocked when Usain Bolt loses, but the fact he ran under 10 seconds last week is ominous. I would be worried if I were his rivals.

The 200m is his favoured event so I expect him to run much more freely in Oslo, especially as he doesn't worry too much about his start in that event.

Oslo isn't the best place to run quickly because of the conditions - it is expected to be 14C and rainy on Thursday - but Bolt has dipped below 20 seconds there in the past and he should win again.

Bolt's losing margin in Rome was fractional and it was his lack of fluidity between 10m and 30m that cost him the race.

I was surprised he ran as fast as 9.95 seconds really, because he didn't sprint - he just ran as he would have done when he was 16.

No matter who you are, when you're competing against the best sprinters in the world, you have to execute the race in the right way - react quickly out of the blocks, drive for 30 metres, get into a nice running phase from 30-70 metres, and then maintain it. He didn't do any of that.

He said afterwards that he didn't feel right, that his legs felt "lumpy", and that's what it looked like. He didn't have any of the transition and that's why I was surprised he ran under 10 seconds.

Bolt's rivals will know he has got more to come. He can finish metres ahead of them when he gets it right, and when it does click he'll quickly dip from 9.9 to 9.7.

After losing in Rome, Bolt said he has lost some motivation, but I can assure you he doesn't like losing - he would rather not compete - and still has ambitions.

Perhaps he lacked motivation for that one race in Rome, but the World Championships in Moscow this August will be enough motivation for him - getting back the 100m title he threw away with his disqualification in 2011.

Even Justin Gatlin, who beat him in Rome, will realise he caught Bolt on a bad day. Normally, he can be a bit off and still have enough in the tank, but when it's a first international race of the season then sometimes things don't quite go to plan.

British sprinters versus Bolt

Daniel Talbot and James Ellington are the two Britons lining up against Bolt in the 200m in Oslo and they need to concentrate on executing their own races.

The Olympic champion is in a different class and they know that. They shouldn't focus on him because he's too good, and they shouldn't try to chase him because that won't happen. They should forget him.

James is running quite well over the distance and he and Daniel need to try to be competitive and run to their season's form.

Ennis-Hill injury a concern for Moscow

It doesn't surprise me that Jess Ennis-Hill has pulled out of Oslo because the warning bells rang once she withdrew from a meeting in Edinburgh last week with an Achilles injury.

I'm worried about her chances of competing in Moscow.

I once damaged my Achilles and it took a long time to get over it. My injury happened in November and I didn't recover in time for the World Championships the following August.

I couldn't train with any force, I couldn't run - I couldn't even do circuit training. I could only do weight training and, as a result, lost all my endurance and technique and that had a knock-on effect on everything else.

It's even more difficult for Jess because she isn't merely preparing for one event. She has to do well in seven events and needs to be 100% ready.

An Achilles injury stops you perfecting things.

When you've sustained a bad Achilles injury you can't even hop, and if you can't hop powerfully then you can't hurdle or practise the long jump. You can't even plant your foot for the javelin.

If she has had an injury-free winter then she's probably been working hard on the weights and, at this stage, what she should be doing is adding endurance and speed work.

If the Achilles is stopping her doing speed work then she's going to be heavy as a result of her weight training. We need her to recover quickly.

All eyes on Perri Shakes-Drayton

This is an important race for Perri. She's had a good indoor season and we expect her to translate the speed she's shown over the flat to the 400m hurdles.

It's important that she races against quality competition. An athlete needs to run against the best in the world as often as possible to get into a groove quickly and be ready for the World Championships.

Competing at a high level and running against faster women will boost her confidence.

She ran a personal best of 50.98secs in Loughborough in May, so we're all rubbing our hands and hoping she can produce that over the barriers.

Perri needs to keep working her technique, speed and approach into every barrier and the only way to do that is by competing.

She has shown huge potential for a long time, even back in 2008 when she won the trials for the 2008 Olympics, and now it's time for her to show what she's capable of doing.

Colin Jackson was talking to BBC Sport's Aimee Lewis.