Rovers completed a deal to bring the experienced striker to the club from Newcastle United in the summer of 2012.
Unfortunately for Leon after a bright start to last summer's pre-season, the striker sustained a cruciate knee ligament injury that meant his first team debut didn't arrive until the following March.
The frontman started his footballing career with Southampton before moving to Coventry City in 2007. His goalscoring exploits saw Newcastle United move for the Republic of Ireland international in January 2010, playing his part as the Magpies returned to the Premier League.
Now free of injury, Leon will be looking for a strong start to the 2013-14 season.