Kai Havertz is not a reliable striker, even he is bad in controlling the ball and as an executor. Kai Havertz needs to be replaced and with Arsenal interest in Gyokeres the only right answer is to get rid of Havertz. Every season Arsenal will always find problems when they are close to trophies, and this season Arsenal will likely be pulled down by Nottongham Forest in the runner up position.
Arsenal do need a more productive striker to highlight their attack and Victor Gyokeres is more productive when compared to Kai Havertz but we also don't know Gyokeres' performance in the EPL because the competition in the EPL is tighter than the Portuguese League, we can see a real example, namely Mbappe, we know he is a potential striker when he was at PSG but when he moved to Madrid everything changed he had difficulty competing in a more competitive League but yes I understand maybe it takes time I think Gyokeres also deserves to be given trust in the EPL.
Hence why they are interested in Gyokeres, but obviously Sporting doesn't want to let him go at this stage of the season. Think about it, if Gyokeres leaves, it's obviously clear that they can't spend all the money and get someone more talented, or even equally talented. So they are going to spend less, and get someone worse.
Even Gyokeres was a big shock, look at his entire career before Sporting and you will see that he was never a great player, never was a premier league top six level player, dude was scoring just a few goals a season at lower leagues at England, and yet he found himself a superstar at Sporting somehow. This means, if Arsenal gets him, then Gyokeres may not be who they think he is, and may not score bunch of goals, but that part doesn't matter to Sporting at the moment. What matters is that he works at the current club, and they are going to have some hard time without a doubt replacing him at the middle of the season so it is a very tough transfer.
Skriniar, Diego Carlos... They are taking really good steps to make their defense stronger. They really needed it because of the vulnerabilities in the area.
Just a few weeks back the media was told that Rash wanted to leave, and any listening Manager will oblige to such requests and be ready to be left out of the starting 11 and am sure because of the offers coming he has seen that he might find himself in a country he doesn't enjoy himself which is sad to be honest. 
