Five things to look for in Champions Cup last 16

After an 11-week hiatus, the Investec Champions Cup returns on Friday with a thrilling last-16 line-up.

The knockout stages get under way with English champions Northampton Saints taking on Clermont Auvergne under the lights at Franklin's Gardens.

BBC Sport highlights five things to look out for across the weekend.

(All times BST)

Friday, 4 April

Northampton Saints v Clermont (20:00)

Saturday, 5 April

Toulon v Saracens (12:30)

Castres v Benetton (15:00)

Leinster v Harlequins (15:00)

La Rochelle v Munster (17:30)

Glasgow Warriors v Leicester Tigers (20:00)

Sunday, 6 April

Bordeaux-Begles v Ulster (12:30)

Toulouse v Sale Sharks (15:00)

Saracens have opted to pursue domestic success over their continental ambitions this season.

The three-time Champions Cup winners have decided to rest several of their England internationals, including Maro Itoje and Tom Willis, for their trip to Toulon.

Director of rugby Mark McCall says he is prioritising making the Premiership play-offs over the chance at a fourth European crown.

Northampton Saints, meanwhile, are the only English side with a home tie after finishing top of Pool 3.

Saints are eighth in the Premiership table after enduring a dismal defence of their title, but Phil Dowson's side will host Clermont in a welcome reprieve from their domestic campaign.

The visitors are sixth in France's Top 14 table after their recent victory over La Rochelle ended a run of five consecutive league defeats.

Clermont booked their place in the knockout stages by snatching a dramatic 33-26 victory in the sixth minute of overtime to qualify at Bath and Bristol's expense.

Elsewhere, Sale Sharks face a daunting trip to six-time winners and defending champions Toulouse, who will be without injured talisman Antoine Dupont after he ruptured cruciate ligaments in his knee during France's Six Nations win over Ireland last month.

Harlequins face an equally difficult task at four-time winners Leinster, while Leicester Tigers travel north to take on Glasgow Warriors.

All three Irish provinces which started in this season's competition have reached the knockout stages.

Leinster lead the United Rugby Championship (URC) and will be targeting a fifth star on the jersey after finishing top of Pool 2 with a clean sweep of four comfortable wins.

Fly-half Sam Prendergast has stepped into retired colossus Johnny Sexton's shoes for club and country seamlessly, while the bulk of Ireland's first-choice pack, including Josh van der Flier and Caelan Doris, ply their trade in Dublin.

Munster finished third in Pool 3 to qualify for the last 16 and they will reunited with their former fly-half Ronan O'Gara in the next round.

They will travel to the Stade Marcel-Deflandre to face the 2022 and 2023 champions La Rochelle, who are coached by O'Gara.

Ireland legends Peter O'Mahony and Conor Murray have retired from the international stage and will want to end their long-standing Munster careers this summer with silverware.

Ulster, meanwhile, won just one of their four Pool 1 games and scraped through to the knockout stages on points difference.

They will face an away trip to title contenders Bordeaux-Begles, who finished top of Pool 1 after four bonus-point wins, including a 40-19 victory when the two sides last met in December.

Defending URC champions Glasgow are flying the Scottish flag in the last 16 after finishing second in Pool 4.

Warriors, who are also currently second in the URC, will welcome Tigers to Scotstoun in fine form after pummelling Johannesburg Lions 42-0 in their most recent outing.

George Horne became the club's record try-scorer in their victory over the South African side, while Leicester were narrowly beaten by Saracens in their last Premiership match.

Tigers are third in the English top-flight and outgoing head coach Michael Chieka says he will work harder to achieve success domestically and in Europe before leaving the club this summer.

Benetton, meanwhile, will make their last-16 debut after a surprise 32-25 victory over two-time champions La Rochelle in their final Pool 2 game.

The Italian side boast a large contingent of the Italy national team, including their fearsome centre partnership of Juan Ignacio Brex and Tommaso Menoncello.

Like Italy, Benetton play a free-flowing brand of rugby and will pose a threat in their trip to French side Castres.

Six of this season's last 16 hail from France.

Bordeaux-Begles made light work of the pool stages and in France wing Louis Bielle-Biarrey, who last month broke the record for the most tries scored in a Six Nations campaign, boast one of the deadliest finishers in world rugby.

Despite the loss of Dupont, Top 14 leaders Toulouse are also among the favourites to secure a record seventh European crown.

Three-time winners Toulon finished top of Pool 4 despite a heavy defeat by Sale Sharks and will be favourites to overcome an under-strength Saracens side.

La Rochelle, meanwhile, are without a win in eight matches since they beat Toulouse in January.

O'Gara has previously led his side to back-to-back Champions Cup titles but he will have to stop this year's rot if he wishes to overcome his former side Munster.

Pool 3 runners-up Castres and Clermont Auvergne make up the French sextet.

It could be another final between the tournament's two most successful sides on 24 May at Principality Stadium as Toulouse and Leinster both ended up on opposite sides of the draw.

Northampton will play a home quarter-final if they can navigate their way past Clermont, while a potential semi-final rematch from last year's competition could await against Leinster.

However, a victory for Quins over Leinster and a Leicester win in Glasgow would also set-up an all-Premiership tie in the next round.

Quarter-final draw (ties to be played on the weekend 11/12/13 April):

Semi-final draw (ties to be played on the weekend 2/3/4 May):