Despite having five months remaining on his contract, the 28-year-old joined Albion at the end of last week for a fee that was agreed upon.
This move was made possible by the activation of a clause in his contract that said he could leave if a Scottish League club showed interest.
Hill said: “To be honest a couple of clubs have been after Robbie this season as he had a clause in his contract which allowed him to move if a league club was interested in him.
“But when we had so many injury problems in the autumn and early winter, he was determined to stay and help out, even when he had the wrist problem.”
Hill said: “A real competitor, he battled hard for the Cowdenbeath cause and was delighted to play anywhere he was needed, whether it was in defence, midfield or up front.
“He will be missed but I fully respect that by joining Stirling Albion he will be teaming up with one of his coaches who worked with him when he started his career at Falkirk and helped him greatly develop his game.”
The manager acknowledged that replacing McNab would be a challenge, but he has plans in place.
Hill said: “Robbie was a real force on the park, as a player and as skipper, and will not be easy to replace.
“However, funds are being made available to strengthen our squad in the transfer window and I have spoken to four players already so hopefully we will have a few new faces in the side soon.”
