Midfield powerhouse Osbourne and winger Sproule have been key figures for the Easter Road outfit, but both have been hit by one-match suspensions, ruling them out of the showdown with Hearts.
But Fenlon, who brought in eight players during the January transfer window, believes Hibs are now better equipped to deal with their Capital neighbours than in the first derby of 2012 in which Hearts cruised to a 3-1 victory to stretch their unbeaten run in the fixture to nine matches.
Fenlon revealed he had already taken into account the fact both Osbourne and Sproule would be missing this weekend when selecting his side for the William Hill Scottish Cup quarter-final clash with Ayr United, wrapping midfielder Tom Soares in cotton wool rather than risking him at Somerset Park.
Soares picked up a “dead leg” in scoring twice as Hibs beat Kilmarnock at Rugby Park, the injury forcing him out of the next match against St Mirren and leaving him “touch and go” for the trip to Ayrshire.
Fenlon said: “Tom was in contention and, if push came to shove, we could have played him. He’d trained for a couple of days but probably wasn’t 100 per cent. With Ozzy and Ivan out this weekend it was important we didn’t lose Tom as well.
“Sometimes these things can backfire on you, but it didn’t, and we now have Tom available again. He has been a bit unlucky not to have got a real run of games. He has been in and out through injury, but he is a quality player and I think we saw against Killie he can finish as well.” In addition to the on-loan Stoke City star, Fenlon feels he now has a greater strength in depth in his squad, better able to cope with the loss of players either through injury or, as in this case, suspension.
He said: “Ozzy has been playing well and will be a big loss but we are two or three months down the line from where we were and it’s not as if we don’t have options.
“We had players sitting on the bench last weekend and others who didn’t make it that far sitting in the stand so it’s not a major concern, we have quality players to bring in, Tom is available and we have others who have not played too much. It’s a decent squad and we can chop and change.”