Sens can't afford to lose a centre with NHL experience.

Yes they can. Stepan, Norris, White, Anisimov, Brown, Galchenyuk, Paquette are all NHL calibre.
Upgrading the defence from Zaitsev to Miller is of bigger importance than who plays 3rd line center.

Stepan and Anisimov are the really only 2 options with experience. Norris literally doesn't have any. Brown doesn't have much at all. Paquette likely won't play too much, if he does it's a 4th line role. White doesn't have much experience at C to consider him a veteran at the position. Galchenyuk has played more of the wing in his career than anything.

You're forgetting that DJ Smith (Sens coach) if very animate with Zaitsev and trusts him. Ottawa added d-man already with Gudbranson and Brown this off-season. They don't need to address it right now when they have guys coking up too. Tier eh is way more valuable for them to keep then to pull something like this off

You're really debating a sens fan about who is more valuable. Norris earned a top 6 spot over Tierney in training camp. Colin White played top 6 with Tkachuk for half of last season and the season before he played with Stone and Tkachuk. He is more than capable of playing 3rd line C and is a bounce back candidate. Tierney is a great player to have but he is blocking younger guys from getting a chance in the lineup. Especially Logan Brown who killed it in the AHL last season yet is still there this season. The sens have no problem offensively. They will struggle defensively and in transition where Zaitsev is weak. Miller is an upgrade over Zaitsev and we save money in the process.

I would rather have 3 years of Okposo than 4 years of Zaitsev

I would rather pay Okposo 18 million over 3 years than Zaitzev 18 million over 4. We already have too many RHDs anyways.

& you think just because you're a fan of the team that what you know is best?

Re-read what I said. I said they don't have enough EXPERIENCE down the middle to afford to lose him right now. I never said those guys aren't capable of playing centre. Norris and Brown are still rookies, no telling what they can handle at the NHL level and centre is one of the hardest positions to adjust to. NHL is a whole different level than AHL. & also as I already said, their coach already has a strong relationship with Zaitsev. He trusts him. & a coach's word goes a long way in who plays.

We don't need any more centermen, we have plenty. "Coach's word goes a long way" How ironic. Tierney could have been our 1C this year but that very coach you mention is playing Norris and Stepan in our top 6 instead because Tierney was outplayed. Coach said Anisimov has been great and I could see him playing 3C for us leaving Tierney on the 4th line. On top of that we have our 2nd line center two seasons ago in Colin White. Coach Smith has Tierney in the bottom 6 where we have plenty of options with EXPERIENCE. We can easily afford to lose Tierney to upgrade a position of need especially after acquiring an identical player in Stepan. So what if DJ Smith likes Zaitsev lol doesn't mean we would never upgrade on him if we had the opportunity. Does this trade seem likely to happen, no, but it would help both teams.