Best is relishing the chance to get his career back on track at Derby, according to Rams boss Steve McClaren.
The 27-year-old striker has joined Championship Derby on a season-long loan deal from Blackburn after an indifferent spell at Ewood Park.
Best joined Blackburn from Newcastle for £3m two years ago but a combination of injuries and poor form saw him struggle to make an impact.
Steve McClaren: “I can sense he is determined to make the most of the opportunity.
"I've spoken to the player and believe he views this loan move as a fresh start.
"We have been keen to add to our frontline during the summer and Leon is someone that we have discussed at length.
"He is a player with Premier League and Championship experience, knows how to score goals and he will provide a different option in our attacking armoury."