Yes, if that's actually "wet", then you do need to be concerned, as it's a sign of a possible upper-respiratory infection. Sneezing, coughing, wheezing when he breathes, shaking his head, etc. are all also signs of this; honestly, just the drainage from his nostrils is enough for him to need a trip to the Certified Avian Vet for a swab/culture of the drainage to diagnose the bacteria/fungi that may be causing this, as well as to identify what antibiotic/antifungal will be effective against it. And be sure to talk to them about giving him the medication by Nebulization rather than just giving it to him orally, as broad-spectrum antibiotics like Baytril (Enrofloxacin) or even the better drugs like Tylosin/Tylan 50 do not penetrate into the upper respiratory or lung tissue well at all when given orally, and it often takes multiple rounds of drugs to cure the URI when given orally, while it only takes a week of a once-daily Nebulizer treatment with Tylosin/Tylan 50 to get rid of it...