The 24-year-old made 215 not out and 109, his fourth and fifth centuries of the County Championship season, in the Bears' win over Nottinghamshire.
Here, the PA news agency takes a look at the statistics that have put Sibley in the international frame.
In a class of his own
Sibley is the only player to have broken the 1,000-run barrier in Division One of this season's Championship, with one round of matches remaining.
He was on 1,000 exactly going into the Notts clash and extended his total to an immense 1,324 – almost 36 per cent clear of second-placed Gary Ballance.
His average of 69.68 is similarly dominant – among players with at least 10 innings, Kent's England batsman Joe Denly is his nearest challenger on 56.00, leaving Sibley 24 per cent clear of the field. Surrey's Ollie Pope and Kent's Sam Billings average in the 70s but have played only seven and six innings respectively, with Joe Root batting three times for Yorkshire including a top score of 130 not out for an average of 148.50 while Aaron Finch scored 90 in his only Championship innings for Surrey.
Four Division Two players have 1,000 runs to their name, though even Glamorgan's Australia Ashes star Marnus Labuschagne is over 200 behind Sibley on 1,114 – admittedly from three fewer innings. Lancashire's Dane Vilas leads the second-tier averages at 84.83 among players with at least 10 innings.
Sibley's tally of five centuries is matched only by Yorkshire star Ballance in Division One, with no other player scoring more than three.
Throw in five half-centuries and he has 10 scores over 50, two more than any other player with Ballance and Hampshire's Sam Northeast tied for second – Northeast has three hundreds and five fifties.
He does not have the highest tally in the "50s" column – that belongs to Yorkshire's Adam Lyth with seven, while Sir Alastair Cook and Chris Nash have six apiece – but that is simply down to Sibley's superb conversion rate.
...and batting long
The need to occupy the crease became painfully obvious as England could only draw the Ashes series 2-2, relinquishing the urn to Australia.
Jason Roy failed to bring his one-day dominance to the Test arena, facing only 229 balls and scoring 110 runs in eight innings, while England found more success after promoting Denly to open alongside the similarly stoic Rory Burns.
Sibley broke through the 3,000 balls barrier for the Championship season in the second innings against Notts, reaching 3,024 – no other batsman has even faced 2,000 deliveries, with Ballance again second best at 1,970.
Inserting Sibley at the top of the England order would allow Denly and Root to drop to more natural positions at three and four respectively, hopefully building a platform for Ben Stokes and co to turn up the firepower from number five onwards.