Bellamy secured a return to Anfield, where he played during the 2006-7 season, late on Wednesday night having been frozen out at Manchester City under Roberto Mancini.
The 32-year-old spent last term on loan at hometown club Cardiff and has not featured in Mancini's first-team squad so far this season.
But his switch to Liverpool means he should see regular game time, which is good news for Speed as his side seek to end a run of four straight qualifying defeats in Group G.
"It's fantastic," he said. "Craig is a quality player, as I have said on many occasions.
"He needs to be playing and I think it's a great move for him. Knowing (Liverpool boss) Kenny Dalglish as I do I am sure he will get the best out of Craig. He is a great man and I think Craig will flourish there.
"It will help him to have his future sorted. It's good for us and I am sure having his future sorted will focus his mind on the game tomorrow night."
Speed insisted that Bellamy's need to leave the squad's Celtic Manor base for Liverpool's Melwood training ground yesterday had not disrupted Wales' preparations.
He said: "It did not disrupt us a great deal. You know the transfer window is there and there were a few lads who made it known they might be here, there and everywhere so we had plans in place.
"Craig left yesterday afternoon, he was back last night and had a bit of a lie-in this morning. We had a chat at the start of the week and made it as least disruptive as possible."
While Bellamy will start against Montenegro, Speed will again be without suspended defender James Collins.
That means Danny Gabbidon and Ashley Williams will continue in defence but Jack Collison's hopes of a midfield place will depend on how he recovers from a stomach bug.
Speed may also be tempted to go with the physical presence of Norwich new boy Steve Morison ahead of the lightweight Robert Earnshaw in attack.