Yorkshire 82 for 2 trail Warwickshire 228 (Patel 63, Pyrah 3-37, Brooks 3-63) by 146 runs

If Yorkshire's ability to cope with the demands of the England selectors is key to their title prospects, then here was evidence that their squad has the necessary depth. With Joe Root, Gary Ballance and Liam Plunkett on international duty, Tim Bresnan nursing a sore elbow and Adil Rashid waiting to nurse a new arrival on extended paternity leave, their numbers were heavily depleted. Yet against another side with designs on the Championship, they ended the opening day in a strong position.

Having dismissed Warwickshire, whom they have beaten by an innings twice in a row, for relatively little damage, they recovered from the loss of Adam Lyth and Jack Leaning in a lively opening spell from Chris Woakes to close at two down after Alex Lees and Andrew Gale added 45 without further alarm.

The understudies who stepped into the spotlight to the most telling effect were Rich Pyrah, the willing allrounder, and Karl Carver, an 18-year-old left-arm spinner who answered the call to be Rashid's stand-in with a nerveless performance that brought him a maiden first-class wicket.

Pyrah is the epitome of the squad player, a solid middle-order batsman with three first-class centuries to his name and more than 50 first-class wickets, but with the temperament to wait patiently for opportunities. Last season he had scarcely a look-in and took two wickets at 122 runs each. This week alone he has five; his 3 for 37 on day one here are the third-best figures of his career.

They were important wickets, too, particularly the first two, which swung the balance of the opening session back in Yorkshire's favour after Warwickshire appeared to be weathering the early loss of William Porterfield, who had been in his best form for the county.

Bowling from the Pavilion End, Pyrah took two wickets in the space of three balls, drawing Varun Chopra forward and finding a thin edge that Jonny Bairstow snapped up, and in the next over bowling Jim Troughton through the gate as the left-hander shaped to drive. Troughton, the Warwickshire captain, was making his first appearance in a Championship match at Edgbaston in more than a year after his long struggle with a back injury.

It meant Warwickshire reached lunch three down having chosen to bat first and they capitulated in the afternoon, losing seven wickets between lunch and tea in a session prolonged to 40 overs because of the nine-wickets-down rule, with Jeetan Patel's boisterous hitting at least enabling them to claim a batting point after being 180 for 9. His unbeaten 63 came off 67 balls with three fours and three sixes.

Carver claimed his maiden wicket when Keith Barker, who was going well on 36, aimed a wild swing in the direction of midwicket and was caught at first slip, one of four catches for Aaron Finch, who might well have taken six had he not been off the field being treated for a groin injury when Rikki Clarke and Tim Ambrose were out, at which moments Lees was standing in for him.

Two of the Finch catches assisted Jack Brooks in removing Sam Hain and Chris Woakes with consecutive balls. He took his 40th wicket of the Championship season later when he bowled Chris Wright middle stump. Only Worcestershire's Saeed Ajmal has more wickets.

Yorkshire will not comfortably build a lead on a pitch that has given the seamers a chance and will probably turn to Patel's advantage under the drying sun. Woakes found something in it, taking the edge twice in the space of four deliveries as Lyth and then Leaning gave catches to the slips.

After his two T20 appearances last week, some Warwickshire supporters thought they might see Jonathan Trott's name on the scorecard. The possibility was discussed after his 39 off 38 balls in front of a large crowd against Worcestershire on Friday but clearly a return to Championship cricket at this stage was not considered appropriate as he continues his recovery from the anxiety issues that surfaced in Australia during the winter.

Dougie Brown, the Warwickshire director of cricket, said last week that it was "highly unlikely" that if Trott declared himself ready to play he would not be picked, so the assumption is that the 33-year-old batsman had the final word on this occasion. Trott's only Championship match so far this season was against Sussex at Edgbaston in April, after which he admitted he was still struggling.