Yes you really need to be averaging at least @40 FC to be considered for a Test cap. Haines looks one to keep an eye on tho, as the leading run scorer this season. Vince is another that has ben tried here and failed. He was Hazlewood's bunny last time he was here for the Ashes or was it in England? As much as I detest an Aussie Sam Robson playing for the old enemy.. he has experience and is in good form. His age, 32, may work against him tho. Sam Hain another Aussie.Just looking at that list and while there are some impressive records in there for the most recent county season, the overall career records are not too great as per below.
Code:Player FC Career Avg Age Notes TJ Haines 34.03 23 Top order batter JD Libby 35.09 28 Top order batter SD Robson 37.58 32 Opening batter DG Bedingham 46.60 27 South African - ineligible MJJ Critchley 32.21 25 All-rounder HM Amla 48.96 38 South African - ineligible BC Brown 40.41 33 Wicketkeeper LJ Hill 28.95 31 Wicketkeeper KS Carlson 31.55 23 Middle order batter OJ Pope 51.23 23 Middle order batter JJ Bohannon 43.97 24 Middle order batter RS Vasconcelos 36.32 24 South African - ineligible BT Slater 33.52 30 Opening batter DL Lloyd 29.42 29 Batting all-rounder MD Stoneman 34.31 34 Top order batter SR Hain 35.94 26 Middle order batter A Lyth 37.78 34 Top order batter JM Vince 39.06 30 Middle order batter CB Cooke 37.75 35 Wicketkeeper HC Brook 27.63 22 Middle order batter
From that list, you can rule out Bedingham, Amla and Vasconcelos as they are all South African so are ineligible for selection. Stoneman and Lyth are also unlikely to be considered, both have played test cricket before and didn't cut it at the level, mostly against Australia in the last series here (2017/18 - Stoneman) or in the home series during 2015 (Lyth).
After those eliminations, there are 15 others to consider, one of whom is Pope who has the best record and is touring here. Some of these players are in the early stages of their career but there are not too many decent records there anyway, Bohannon played in the England Lions side against Australia "A" earlier in the season while one wonders why Ben Brown (averaging 40.41 as a wicketkeeper) hasn't got more of an opportunity. Sam Robson played test cricket seven years ago but hasn't received an opportunity since while James Vince has been in and out of the side for some time.
After this test series has been completed, the England selectors will have some decisions to make regarding the batting order and how many of this side will continue for their next series against West Indies in March before their home summer then begins. The coming county season could provide crucial as there may be some spots up for grabs, particularly for their home summer.