Every side wants an unplayable legspinner. But not unplayable in this sense. Eoin Morgan's decision to pull Joe Denly out of the attack after just one over of the Bristol ODI surely ended the player's hopes of featuring in the World Cup. It suggested the captain had little faith in Denly's abilities. It suggested he had seen enough.

You couldn't really blame Morgan, either. There were three full tosses in that Denly over and, while it cost an unremarkable nine runs, it's hard to set a field to that sort of bowling.

Nor was this a unique experience. Morgan had also felt it necessary to remove Denly from the attack in Cardiff after just one over. On that occasion, Denly had started with two long-hops that were pulled for six.

Shortly after his spell in Bristol ended - if you can term one over a spell - CricViz produced a statistic stating that Adil Rashid and Denly had both bowled four full tosses in ODI cricket this year. The difference is that Rashid has delivered 270 balls and Denly just 36.

If Denly were in the squad primarily for his batting, England might be able to ignore such statistics. But he has been selected primarily to ensure England have cover should either of their two main spinners suffer injury: he had been slated at No. 7 in this rejigged line-up. On the evidence we have available to us - and, to be fair to Denly, he hasn't had as much opportunity to bowl as he might have expected - he is not up to the job. There is no way England could go into a World Cup game expecting Denly to get through 10 overs. Even four or five would seem to constitute a huge risk.

There were repercussions for Denly's struggle here. It meant that England bowled relatively little spin - only seven overs in total - which contributed to their over rate being horribly slow. The Pakistan innings finished 29 minutes later than scheduled which seems certain to lead to heavy fines and perhaps even a suspension for Morgan, who was also penalised for a slow over-rate after the second ODI in Barbados.

The ICC's regulations ensure that Morgan's involvement in the World Cup will not be compromised - suspension and demerit points from bilateral series are not carried over into global tournaments - but it would not be ideal to be without the captain in the final stages of the planning process.

It also underlined how important Rashid is to England's World Cup hopes. It's not just the variation and wicket-taking threat he offers, it's also the fact that he helps England get through their overs in an acceptable timeframe. He remains integral to their hopes.

Still, Morgan could have made more of the spin resources he had available. Moeen delivered only six overs, despite being England's most economical bowler, while Joe Root was once again not asked to bowl at all. The short straight boundaries may well have influenced Morgan's decision but the absence of spin rendered England's attack - full of seamers operating at around 81 mph - a little samey. Jofra Archer, Mark Wood and Rashid might all have added some variety.

The other repercussion may well be a call-up for Liam Dawson. He is, in many ways, an unlikely saviour. But he is a far more experienced and proficient spin bowler than Denly and an almost equally proficient batsman and fielder. It would be brutal to make such a change in mid-series but, with only two more ODIs - and two more warm-up matches - ahead of the World Cup, there is no time to be wasted in familiarising Dawson to England's game plans and allowing him some acclimatisation time.

Denly is a fine cricketer in many ways and may yet return to the England side for the Ashes. But there was always an element of wishful thinking involved in casting him in the role of legspinning all-rounder and for the selectors to continue to ignore the evidence would be obtuse and damaging.

There could be another way. Rather than playing a utility player like Denly, England have the all-round strength - they utilised seven bowlers in this game - to play a specialist keeper in Ben Foakes who might be more willing and able to stand up to the stumps to the seamers. Had a keeper been able to do that here, it may have forced the batsmen to think a little harder before they skipped down the wicket to hit the seamers off their lengths.

It was a tactic employed successfully by Jack Russell when Gloucestershire won a limited-overs treble, by Keith Piper when Warwickshire won six trophies in 25 months and in the 2012 CB40 final when Michael Bates memorably stood up to Kabir Ali. There seems no chance whatsoever of it happening now, but it might be worth thinking about ahead of the T20 World Cup next year.

In the short-term England have more pressing matters to think about. Denly's inclusion currently looks like a weak link in an otherwise well-constructed squad. There's still just about time to call up Dawson, but they have to act decisively and immediately.

George Dobell is a senior correspondent at ESPNcricinfo