England's selectors have chosen to delay the announcement of their first Test squad of the summer, originally scheduled for Monday, to enable the players to have an extra round of county matches in which to prove their form.

England had been expected to name an enlarged squad of 15 or 16 players for the first Test against West Indies at Lord's starting on May 6, but with several key players away in South Africa with the IPL, and others, such as Michael Vaughan, having had limited opportunities to push their case so far this summer, that decision has been pushed back to April 29. It will also give the new coach, Andy Flower, longer to bed down in his new role.

Geoff Miller, the national selector, said: "The selectors have met but have decided that we need more time to assess players who are returning after injury. We also felt that by delaying the selection for the first Test it allowed us the opportunity to see another round of County Championship matches before deciding on the squad."

Vaughan, who hasn't featured in an England squad since announcing his resignation from the captaincy in August last year, is one player who could benefit from the postponed announcement. He made just 12 while playing for MCC against Durham in the season curtain-raiser at Lord's earlier this month, but will get another opportunity to impress in Yorkshire's first Championship match of the season, also against Durham, at Chester-le-Street on April 22.

He is one of up to four players competing for England's problematic No. 3 position. Ian Bell, the long-term incumbent who lost his place in the Caribbean in February, proved his form with an impressive 172 for Warwickshire at Taunton this week, to put the pressure back on his rival Owais Shah, who is one of five players in South Africa with the IPL.

Other injury concerns include Alastair Cook, who fractured a finger recently in the Es+++ nets, as well as the Nottinghamshire pair of Ryan Sidebottom, who pulled up lame during the Caribbean tour, and Graeme Swann, who bowled with an elbow injury during the closing stages of the Test series, and missed the subsequent one-day victory. Their campaign gets underway against Worcestershire at Trent Bridge on Tuesday.

On Monday, the selectors will announce the England Lions squad to face West Indies at Derby on April 30, which may offer Sajid Mahmood among others an opportunity to build on the progress he made with the team in New Zealand this winter. The squad and captain for the ICC World Twenty20 will be revealed on May 1, along with the squad for the three ODIs against West Indies.