The casualty rate ahead of the Cheltenham Festival means that the winners of the five main events from last year will not be present at Prestbury Park next month, we take a look at who's missing and why.

The news that Thistlecrack will not line up at the upcoming Cheltenham Festival only adds to the number of high-profile absentees from next month's Prestbury Park extravaganza.

Word came through on Tuesday that Colin Tizzard’s nine-year-old and Gold Cup favourite will miss the remainder of the season due to a tendon injury

Thistlecrack stormed up the hill to win the World Hurdle in fine style in 2016. Equally impressive in winning the Festival’s standout races 12 months ago were Annie Power, Sprinter Scare, Vautour and Don Cossack. That quartet will also be absent when the tapes go up underneath Cleeve Hill in three weeks time.

A disappointing pre-cursor to an event that thrives on seeing past champions coming back to defend their crown.

Annie Power – Champion Hurdle

Having finished runner-up in the 2014 World Hurdle and fallen at the last with the Mares' Hurdle at her mercy 12 months later, the popular nine-year-old brought the house down when breaking her Festival duck in becoming the first mare in 22 years to claim Champion Hurdle glory last March.

She followed up in style at Aintree the following month.

Trainer Willie Mullins had hoped that the mare would make her seasonal bow at Punchestown tomorrow, but a leg injury sustained at the end of January put pay to the nine-year-old defending her crown on 14 March.

It’s unlikely that Annie Power will see any action this term.

Sprinter Sacre – Champion Chase

After winning the two-mile chase highlight in 2013, Nicky Henderson’s 10-year-old regained the crown in heart-warming scenes last March.

After suffering from a fibrillating heart in December 2013, he was nursed back to his best by Henderson to rule to two-mile division once more.

Sprinter Sacre endured his fair share of setbacks throughout his career and last November, Henderson decided that retirement was the best option for his stable star, who won 18 of his 24 starts and amassed £1,136,000 in prize-money.

Vautour – Ryanair Chase

Vautour was among the favourites for last year’s Gold Cup, but he was rerouted to the Ryanair at the 11th hour, winning in dominant style.

Recruited from France, Vautour won in his first six starts for Willie Mullins, including the Supreme Novices at the Festival in 2014. The following year he claimed the JLT at Prestbury Park

His final race saw him placed second behind Gods Own in last season’s Punchestown Champion Chase.

On 6 November last, Vautour died as a result of a freak accident at Williw Mullins’ yard.

The three-time Cheltenham Festival winner was put down after breaking a foreleg.

Thistlecrack – World Hurdle

A slight tear on the tendon means that Thistlecrack will not line up in the Gold Cup on 18 March.

After blazing a trail in the staying hurdle division last season, that culminated in his victory in the Ryanair World Hurdle, Thistlecrack then made a mark over the larger obstacles this term.

An impressive victory in the King George at Kempton cemented his place at the head of the market for the blue riband event. And even though he suffered a narrow defeat to the ill-fated Many Clouds at Cheltenham on 28 January, he still retained favoritism for the feature event.

Don Cossack – Gold Cup

Owned by Michael O'Leary's Gigginstown House Stud, Don Cossack held off Djakadam to win the most prestigious prize in National Hunt racing last March.

He subsequently suffered an injury when being prepared for the Punchestown Festival but had been working towards a return to action this month.

However, on 11 January, trainer Gordon Elliott reported Don Cossack to have heat in his leg, with connections opting to retire their star performer.

Don Cossack had won six of his last seven starts, with his sole defeat coming when hitting the deck in the 2015 King George VI Chase at Kempton.

Reflecting on the career of the 10-year-old, Elliott told RTÉ Sport: “His best performance was probably his last run in the Gold Cup.

“It’s a shame he had to be retired, but it was a privilege and I was very, very lucky to train a horse like him.

“He’s a horse that will always be very close to me and all the staff.

“We’ll never forget him and we’ll be lucky to get another one like him ever again.”