For legendary Shane Warne, no quality back-up in sight to premier Australia off-spinner Nathan Lyon is a "real issue". The former leg-spinner is especially worried over the trend of First-Class teams in the country not fielding any spinner in their line-up for certain rounds of Sheffield Shield at the start of the summer. 

While at times we've seen the likes of Jon Holland, Steve O'Keefe or Ashton Agar turn up as the second spinner for Australia, the gap in skillset between them and Lyon is huge. The 31-year-old has now played 91 Tests with 363 wickets - the highest for an Australian off-spinner - at an average of 32.3. 

"Luckily we have such a quality spinner in Lyon, he's done so well in all conditions around the world, held that attack together, but if something happened to him it would be a real issue," Warne was quoted as saying by ESPNcricinfo. 

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"It's important for Australia - I'm not saying Lyon is retiring or anything, he's got a lot more in him - that if something does happen for Australia that someone could set up."

With spinners being picked sporadically on surfaces offering excessive movement and bounce to seamers, Warne said the domestic teams shall always field one in their line-up for the future benefit of Australian cricket. 

"They should always pick a spinner, it's disappointing if sides are not picking spinners regardless of conditions we should be encouraging spinners in all forms because they'll learn how to bowl in different conditions."

"The job of Sheffield Shield sides is to make sure you are producing international cricketers, it's not just looking after your own state. You have to make sure Australian cricket is strong and they should be picking spinners," Warne concluded. 

(Inputs from ESPNcricinfo)