Andre De Grasse has done a lot of things well this season in his injury return, from working diligently in a new training environment, to reaching the podium in all eight of his combined 100- and 200-metre races, to consistently lowering his times.

He's even "close" to taking back his Canadian sprint titles from Aaron Brown, according to his American coach and sprint guru Rana Reider.

"But if you look at the way I want him to race, it's not there yet," Reider says over the phone from Germany before travelling to London, where De Grasse will race the 100 on Saturday at the Müller Anniversary Games.

"Do I think he has it physically? Yes, 100 per cent. But to be a good starter, to be a guy that's going to be in the mix at 30 metres, we have to change the ability to really push buttons. We all know he's got the top-end speed from 30 metres on."

For De Grasse to close the gap on the likes of Christian Coleman, Noah Lyles and Justin Gatlin — each of whom has run sub-9.90 seconds this season — the 2016 triple Olympic medallist has to be quicker and more efficient to the 30-metre mark.

"He has to be in better body position and has to be able to get there and not use up so much energy that it costs him at the end of the race," Reider says. "He was a better starter [in 2016] so it could have been the injuries or a lot of things for why he has gone backwards."

WATCH | Andre De Grasse breaks down the 100 metres:

The 100m seems to go by in a flash, but 3-time Olympic medallist walks you through all of the different things that can happen within only 10 seconds or less on the track. 2:18

2 hamstring injuries in less than a year

De Grasse, 24, was forced to cut short his 2018 season short in July after suffering a Grade 1 strain in the biceps femoris — one of the hamstring muscles at the back of the thigh — during the 200 semifinals at the Canadian championships in Ottawa.

"There are a lot of people to fill <a href="https://twitter.com/usainbolt?ref_src=twsrc%5Etfw">@usainbolt</a> 's shoes" - <a href="https://twitter.com/De6rasse?ref_src=twsrc%5Etfw">@De6rasse</a> on the fierce competition in the men's sprints.<a href="https://twitter.com/hashtag/LondonDL?src=hash&ref_src=twsrc%5Etfw">#LondonDL</a><a href="https://twitter.com/hashtag/DiamondLeague?src=hash&ref_src=twsrc%5Etfw">#DiamondLeague</a><a href="https://twitter.com/hashtag/RoadToTheFinal?src=hash&ref_src=twsrc%5Etfw">#RoadToTheFinal</a> <a href="https://t.co/qKrwfof4v7">pic.twitter.com/qKrwfof4v7</a> —@Diamond_League

In August 2017, De Grasse dealt with a more serious Grade 2 strain sustained during a training run just days ahead of the world championships at London Stadium, site of this weekend's two-day Diamond League track and field event.

The talent's there ... we're training well and have had some good races, but we're not completely back to where we need to be. — Rana Reider, Andre De Grasse's coach

Looking to make a change last winter, De Grasse left coach Stuart McMillan of the Phoenix-based ALTIS training group and moved to Jacksonville, Fla., where he hooked up with Reider.

Together, they worked together to slowly build De Grasse's physical capabilities and confidence after injuries and a bout with mononucleosis at the start of the 2018 campaign left the runner wondering if he would regain his 2016 form that saw the Markham, Ont., native post personal-best-times in the 100 (9.91) and 200 (19.80) at the Summer Games in Rio.

"We came to the conclusion we could get him back on the road to success," Reider recalled. "He was pretty hyper sensitive to every ache and pain he was feeling and afraid to do a lot of stuff. It was a slow process to getting him comfortable training again.

"The talent's there … we're training well and have had some good races, but we're not completely back to where we need to be."

WATCH | Christian Coleman rules the competition at Prefontaine Classic:

Christian Coleman ran a 9.81 in the men's 100-metre race at the IAAF Diamond League event at Stanford University. 4:21

Hughes, Blake also in field

Reider points out De Grasse's 10.05 season-best, while okay coming off a serious injury, is "below average" for the time the coach believes he can and should be running. With world championships in two months, De Grasse continues to work on developing the mindset of being an aggressive 100-metre sprinter.

"We do four gym sessions a week and we're on the track six days a week. We haven't backed off at all," says Reider. "If you're running against Noah Lyles, Coleman and these other guys, you're going to get exposed if you're not doing the work properly. For Andre, it's having the mindset of knowing you're going to be a 9.90 runner when you need to."

WATCH | Andre De Grasse places 2nd at Ostrava Golden Spike:

Andre De Grasse sprinted to second place in 10.05 seconds at the Golden Spike event in the Czech Republic. 2:19

The "other" guys in Saturday's field to watch are Zharnel Hughes of Great Britain, Jamaica's Yohan Blake and South Africa's Akani Simbine. Two heat (semifinal) races are scheduled for 9:35 and 9:45 a.m. ET, respectively, with the final at 10:50.

Hughes, 24, went to high school in Jamaica and trained with 100 world-record holder Usain Bolt and Blake. He clocked a season-best 9.97 in his most recent 100 on June 30, placing third at the Prefontaine Classic in Stanford, Calif.

"He's a big kid and when he figures things out, can probably run 9.70, even 9.60," says CBC Sports track analyst Donovan Bailey. "He's a huge talent."

WATCH | Anson Henry on who will take over from Usain Bolt:

With the departure of Usain Bolt, who is going to step up to the throne as The Fastest Man in the World? CBC Sports Anson Henry breaks it down. 2:32

Emotional return

Blake, 29, was the 2011 world champion and beat Bolt at the 2012 Jamaican Olympic trials but has been slowed by a series of leg injuries since 2013, though he posted a winning time of 9.96 at the Jamaican championships on June 21.

Simbine, who was bothered by hamstring soreness last season, won the 100 at the Boston Games athletics meet in 9.92 in mid-June. On May 18, the 25-year-old ran 9.95 at Shanghai Diamond League.

"In the first year, I didn't want to watch it" - <a href="https://twitter.com/De6rasse?ref_src=twsrc%5Etfw">@de6rasse</a> on watching athletics while he recovered from injury.<a href="https://twitter.com/hashtag/LondonDL?src=hash&ref_src=twsrc%5Etfw">#LondonDL</a><a href="https://twitter.com/hashtag/RoadToTheFinal?src=hash&ref_src=twsrc%5Etfw">#RoadToTheFinal</a><a href="https://twitter.com/hashtag/DiamondLeague?src=hash&ref_src=twsrc%5Etfw">#DiamondLeague</a> <a href="https://t.co/fuBQhmlY4Y">pic.twitter.com/fuBQhmlY4Y</a> —@Diamond_League

Many eyes will also be on Great Britain's James Ellington, who last competed in August 2016 before he was seriously injured in a head-on motorbike collision while training in Tenerife, Spain.

The 33-year-old had three surgeries after breaking the tibia (shin bone) and fibula (calf bone) in his right leg. Ellington, who has a 10.04 personal-best time, also sustained a displaced pelvis and broken eye socket in two places.

Other Canadians competing in London:

Saturday – Alysha Newman (pole vault, 9:09 a.m. ET), Liz Gleadle (women's javelin, 9:20 a.m.), Gabriela DeBues-Stafford (women's 1,500 metres, 10:39 a.m.)

Sunday – Christabel Nettey (women's long jump, 9:40 a.m.), Jessica O'Connell/Andrea Seccafien (women's 5,000, 9:56 a.m.), Sage Watson (women's 400 hurdles, 10:29 a.m.)

Diamond League on CBC Sports

CBC Sports is providing live streaming coverage of all 14 Diamond League meets this season at CBCSports.ca and via the CBC Sports app for iOS and Android devices. TV coverage will be featured as part of the network's Road To The Olympic Games weekend broadcasts throughout the season.

The following is a list of upcoming Diamond League meets, all times ET: