Pakistan coach Mickey Arthur is hopeful that the time of the year will help them overcome the loss of legspinner Yasir Shah for the Tests against Ireland and England.

Yasir has taken 89 wickets in the last two years - more than double Pakistan's next most successful bowler in the period - but was ruled out of this tour due to a hip injury. Shadab Khan, the 19-year-old legspinner, who has impressed with the white ball but has played just one Test, has huge shoes to fill although there remains a chance Pakistan will decide to go without a specialist spinner given the early-season conditions which are likely to prevail.

There has been a significant decline in Pakistan's Test fortunes since the shared series against England in 2016 which helped them to the No. 1 ranking. They are now languishing at No. 7 following series defeats against New Zealand, Australia and most recently Sri Lanka - their record with Arthur as coach is 11 defeats and six wins from 17 Tests - and are going through a transitional phase following the retirements of batting stalwarts Younis Khan and Misbah-ul-Haq.

There are four uncapped batsmen in the squad and the absence of Yasir has shorn Pakistan of a senior figure with the ball while also leaving them with their least experienced spin attack to face England in at least 40 years.

"Any team would miss Yasir," Arthur said ahead of the team's first warm-up match against Kent. "He has the ability to hold the attack and control the game. Shadab is incredibly exciting but also I am not sure that spin is going to be a huge factor given it's early season in England, so we have covered ourselves in the seam department. But Shadab can clean tails up because he has all the tricks. It is going to be exciting to see how he goes.

"Yasir is a big loss but we have him at the National Cricket Academy [in Lahore] and he is getting fit, his stress fracture is healing and it's really important for us to have him fit and firing for the Australia and New Zealand series later in the year."

Pakistan's bowling attack will rest heavily on Mohammad Amir, who arrived in the UK on Wednesday having been granted his visa after a short delay. Two years ago he made his return to Test cricket at Lord's, following his spot-fixing ban, and since then has not earned the rewards his bowling has often deserved with 44 wickets at 37.25. How Pakistan catch will be a critical factor, with Amir suffering significantly from missed chances, although there is also a belief in the team management that the amount of white-ball cricket he has played has led him into bowling too short with the red ball.

"He's our No. 1 bowler, we back him in tough situations. He generally gets it done for us," Arthur said. "We need him to get the ball swinging, we need him to get his length slightly fuller and if he gets that he's going to ask a lot of questions."

Amir's workload has also become a topic of debate in recent times, with the indication that he may sit out some Test cricket to preserve him for the 2019 World Cup and beyond. Arthur said that Pakistan have "three weeks off" between now and the World Cup, leaving a balancing act between building a new era for the Test side while keeping an eye on the demands of the limited-overs game.

"We have had the workload debate for a long time now and every team has to do the same. We only have three weeks off in our calendar now before the World Cup next year, so we'd be silly not to arrive here with our bowlers fit and we know who they are - we have identified them - so we just have to manage them because ultimately want the best team to play in that 2019 World Cup.

"But also for us it is so important to win Test matches - we are a young team and we need to get our Test team right and to do that we have to build a core of players who can play at any given time. We are trying to resurrect our Test side, we feel we've got our white-ball cricket where we need it now, so we are really excited about this series, really excited to see these young guys come out and perform. There's some incredible talent in our dressing room, so let's hope it all goes well for us."