Suarez is getting old. If we don't start looking for a suitable replacement soon, we will end like Slovenian national team, who still had Novaković camping up front at 37.
We need another forward who is willing to defend. Now, with Messi and Suarez, we are defending with 8 outfield players and naturally, our midfield is knackered. Messi has earned that luxury (to not need to defend). But we would've been so much better if we had 2 forwards out of three defending, not one. That's why we are looking at Griezmann. He always tracks back. That would also help Dembele with his defensive duties, which would've been good and would also mean more playing time for him.
Edit: Oh, hi, JamDav. Haven't seen you for a while.