Ennis-Hill, Johnson-Thompson and Lake give Gunnell optimism

Jess Ennis-Hill (l) and Katarina Johnson-Thompson are friends and rivals

Former Olympic champion Sally Gunnell is impressed with the wealth of talent Great Britain has at its disposal in the women's heptathlon.

World and Olympic champion Jessica Ennis-Hill has Katarina Johnson-Thompson and teenage sensation Morgan Lake snapping away at her heels as the trio build up to this summer's Games in Rio.

Johnson-Thompson was left disappointed after long jump in Beijing

Johnson-Thompson looked on course to challenge Ennis-Hill for the gold medal at last summer's World Championships in Beijing, before failing to record a distance in the long jump after her three efforts were deemed illegal.

But Gunnell, who scooped 400m hurdles gold at the 1992 Olympics in Barcelona, expects Johnson-Thompson to bounce back and admits she is also excited about World Junior champion Lake.

"We're really strong in the heptathlon at the moment," she told Sky Sports.

Gunnell is excited by the British heptathlon trio

"We've got Katarina Johnson-Thompson and Morgan Lake and both of them are just on the cusp, especially Katarina.

"She was very unfortunate last year to have mucked up in that long jump but you can't write her off from getting a medal or even a gold medal [at Rio] this year.

Gunnell is convinced Ennis-Hill and Johnson-Thompson are Rio medal contenders

"Disappointment and being able to move on from is part of what athletics is about but that's what makes you. It is part of what you have to go through to reach that pinnacle.

"I'm convinced she will be right up there this year and she will probably be one of Jess' main rivals in 2016.

Morgan Lake won both high jump and heptahlon gold at the 2014 World Juniors

"I think with Morgan we forget just how young she is. She's there and she's on the scene winning what she needs to at this age. Hopefully she can get to Rio, be part of that team and get that experience, which is what she needs for the future. 

"She's won so much in the juniors and people will expect a lot from her but we have to remember she is still only young. Your body changes at that sort of age as well, so she has a lot to deal with but she has got great promise for the future."

Ennis-Hill celebrates after winning heptathlon gold in London

Gunnell believes Ennis-Hill, whose Beijing triumph came 13 months after giving birth to her son Reggie, is benefiting from the presence of two world-class domestic rivals in Johnson-Thompson and Lake.

"I think it has already [brought out the best in Jess]," Gunnell said.

Ennis-Hill won 2015 Sunday Times and Sky Sports Sportswoman of the Year

"When she came back to training last year she knew that Kat was going to be on her heels and she knew this new young blood in Morgan was there coming through.

"Of course that spurs you on. You don't want to be beaten by somebody from the same country, but sometimes you need that to give you the motivation to go out there and put in the long hours training. I'm sure that helped her all the way through last year."