The 20-year-old, who has joined on a three-month loan move from Manchester City, didn't travel to south-east London for today's npower Championship clash at Crystal Palace but is likely to be in the squad for Tuesday's Carling Cup game between the sides.
"He will add a bit of variety to our frontline," said Mowbray. "Scott and Marvin worked extremely hard again against Palace but it would be nice to take one of them off every now and then after an hour.
"If Alex scores some goals he will hopefully play some games and I can give the others a rest.
"We've tried to bring in different types of striker and it's something we're still trying to address."
A prolific goalscorer at youth and reserve team level, Nimely has also played for both England and Liberia at U-20 level.
City rated him highly enough to tie him down with a new four-year contract last April.
Born in Liberia, Nimely left his homeland at an early age and caught the eye of several clubs after settling in England.
Snapped up by City, he thrived at their highly-successful Academy and enjoyed a prolific 2008/09 season, blasting more than 30 goals and adding another 10 after graduating to reserve team football.
He made his first team debut in a 6-1 win over Burnley at Turf Moor.
Although he has represented Liberia U-20s, scoring 15 goal in just 11 games, he later pledged his international allegiance to England and scored their only goal in the 2009 U-20 World Cup finals, in the final group stage games, against Uzbekistan.