You'd imagine there would be a phasing out time if in reality we have nothing to play for towards the end of season. That will at least give us an idea of if we can cope with a Mina/Keane partnership. If it doesn't then like
@Eggs said least we have an idea what qualities we need when we go shopping for one.
For those reasons it isn't the worst thing in the world, we probably loaned Zouma for cover while Mina was getting fit, knowing that we would only throw Jags in as a last resort. We are still in that transition period where we'll struggle to get the targets we really want, so loans do make sense in the way if we can use them to get the club closer to the top 6, we start to become attractive to the ones we would want to sign permanently.
The club I suppose would also hold out hope that if we have a decent season then players like Gomes and Zouma, getting regular games may just think that it isn't too bad here, where they may not have joined if the only option was a full transfer which would likely be seen as a massive step down.