Jonny Bairstow and Eoin Morgan gave England a confidence boost on the first day of their second tour match in India, but the identity of Alastair Cook's new Test opening partner remains uncertain.

Bairstow (118) made his maiden first-class hundred in an England shirt as England notched up 338 for six on day one of three against Mumbai A at the Dr DY Patil Sports Stadium, and shared a stand of 158 with Morgan, who himself made 76.

However with Nick Compton registering another failure and Joe Root (28) only faring marginally better after the duo opened the innings together, with Cook sitting the game out, it remains unclear who will bat alongside Cook in the first of four Tests against India.

England's early troubles, with Jonathan Trott also making 28 and Ian Bell falling for four, meant that they found themselves in the worrying position of 66 for four before Bairstow and Morgan lifted the tourists towards a very respectable score.

Compton had his off stump removed by Kshemal Waingankar, while Root was caught at short-leg off the part-time bowling of home captain Suryakumar Yadav.

Meanwhile Trott followed a half-century with Root with an edge behind, before Bell was also caught behind by wicketkeeper Sufiyan Shaikh when Waingankar found the edge with movement off the pitch.

Morgan led the counterattack for England, smashing a huge six off Yadav in an 81-ball 50, which also included six fours.

Yet it was Bairstow, scorer of 95 and 54 in England's most recent Test match at Lord's, who was able to convert his innings into a three-figure score and provide the selectors with a firm reason for his inclusion in the middle order.

Shardul Thakur eventually had Morgan lbw with a yorker, but Samit Patel (59 not out) continued his fine form with another 50, in only 60 balls, to see Bairstow to his hundred.

Bairstow's innings came to an end shortly before the close of play when he edged Javed Khan low to first slip.