Earnshaw joined bottom-of-the-table Derby last summer for a club-record £3.5million from Norwich City where he had scored 27 goals in 47 appearances.

Yet despite such a superb goalscoring record, Earnshaw has failed to nail down a place in the Rams starting line-up, either under former coach Billy Davies or current manager Paul Jewell.

The Wales international, omitted from John Toshack's latest squad for the first time in six years, has made just six starts all season, with his 14 other appearances as a substitute.

But Earnshaw, who has scored just one goal for Derby this season, said: "I believe I'm twice, three times a better player than I was at the start of the season because I've learned so much.

"When you play against one of the best teams in Manchester United as we did on Saturday (losing 1-0) and you push them to the limit, that's a measure of where you are.

"I've been very pleased with my performances in all the games in which I've started and I'm very glad I've not let myself down. But I've learned a hell of a lot, I've showed what I'm about."

 Paul Jewell's side travel to Middlesbrough on Saturday in the Barclays Premier League.