Andy Johnson was 22 when Johnson ended the season as top scorer in the English First Division (now the Football League Championship) in the 2003-04 season with 32 goals. Palace reached the Playoffs and were promoted to the Premiership for 2004-05.
Kevin Doyle was 22 when he started knocking in the goals for Reading last year, and 23 this season.
Our own Jason Roberts was 24 when Despite being fully fit for 2002-03, Albion's first season in the Premiership, Roberts managed only 3 goals in 31 games.
Zamora was 23 -In January 2004 he joined West Ham, swapped for Jermain Defoe
Marlon Harewood was 25 - He returned to top flight football following West Ham's playoff victory at the end of the 2004-05 season, and the 2005-06 season saw Marlon spearheading Pardew’s Premiership attack. He scored 14 league goals
Louis Saha was 23 when Fulham first made it into the Prem.
Viduka didnt make the Prem until 25 - The Leeds United manager David O'Leary swooped for Viduka just before the 2000-01 season after tracking the big Aussie striker for some time
too many players to go through Only the exceptional talents breakthrough at 20,21. Derbyshire has a few more years before people can start writing him off, lets not forget at the moment he's currently got the build and stature of a teenager, hes most likely a late developer, Im sure once he starts to develop more muscle we'll see a much stronger player, a bit like Bentley who was same when he first started games here.