Mako Vunipola© Photo by David Rogers/Getty Images

The pain of losing two finals last season is still a huge motivating factor for Saracens as they prepare for their Aviva Premiership semi-final, according to Mako Vunipola.

Last May was a month of heartbreak for Saracens as they got to both the Heineken Cup and Premiership finals only to lose both. But now as they go through the final stages of their preparation for the trip to Northampton on Saturday, Vunipola says the anguish they suffered last May is being transferred into motivation. They know a win will see them book their second final spot on the trot with either Bath or Leicester lying in wait.

"This weekend is huge; we are using last year's results as motivation," Vunipola told ESPN. "We were so close but we have to go one step further. It is added fuel to the fire.

"It was a lot harder for the boys [who went to New Zealand on the England tour] as they didn't have much time to switch off. Some boys still feel it now. To get to two finals is a massive achievement and to lose both was gut wrenching. We still think about it now and it is motivation."

Mako Vunipola© BT Sport

Vunipola was included in England's 50-man World Cup training squad on Wednesday and he will be hopeful of making the final 31-man cut. It has been a frustrating season for Vunipola on an international basis as he was forced to miss their tour to New Zealand and also the November Tests due to a dislocated knee. He did return for the Six Nations but was second choice behind Joe Marler.

Though it was a frustrating experience at the time, Vunipola now views his time on the sidelines as a blessing in disguise.

"It was hard at first but now I'm back playing and you see how the guys are who have played the whole year, they are struggling. It is more a mental struggle than anything, they are mentally fatigued.

"It was frustrating not to be involved at the start of the year with the injury. More than anything I knew I wasn't at full level and I was off a little bit. That was very frustrating. It's nearly a year now since I had the injury and everything is going well. I just want to play as well as I can before a big summer. I still feel I can improve and I feel I can give a lot more to Saracens.

BT Sport is the exclusive home of Aviva Premiership rugby. Watch both Aviva Premiership Semi Finals on May 23, and the Final from Twickenham on May 30, exclusively live on BT Sport 1.