Owusu is in his second spell at the club, after rejoining from Championship side Reading in the summer.
And he is beginning to hit form at Griffin Park, scoring in his last two games.
Allen said: "Lloyd has been playing very well. He was outstanding when we won 2-1 at Hartlepool last Saturday, and deserved his goal.
"And he scored another [to get us a 3-3 draw against Oldham] on Saturday, which the fans were extremely relieved about."