Defending champions Barcelona take on Athletic Bilbao tonight in the opening match of the 2019-20 La Liga season, as Lionel Messi & co. look to put the demons of last season to rest.Although the Blaugrana comfortably won the 2018-19 La Liga title to register their 8th league triumph in the last 11 seasons, Spanish coach Ernesto Valverde was close to getting the axe after Barcelona were eliminated in dramatic fashion by Liverpool in the UEFA Champions League semi-finals. To add insult to injury, the Catalans were upset in the Copa del Rey final by Valencia.Barcelona have brought in some star reinforcements over the summer, including Dutch midfielder Frenkie de Jong and French forward Antoine Griezmann. With the team performing inconsistently in the pre-season matches, Valverde has many areas of concern to address as the Blaugrana look to challenge across all fronts this season.🔥 TOMORROW 🔥🙌 TOMORROW 🙌🤩 TOMORROW 🤩We're just 24 HOURS from the start of #LaLigaSantander 2019/20!#HolaLaLigaSantander pic.twitter.com/cLWGZ1QFF1— LaLiga (@LaLigaEN) August 15, 2019#3 Fitting in the newcomersWhere do de Jong and Griezmann fit in?With Messi still recovering from injury, and unlikely to start, Valverde is likely to rely on newcomer and ex-Atletico Madrid ace Antoine Griezmann to provide the creativity for Barcelona going forward.The 28-year-old Frenchman was slow to get off the mark in Barcelona's pre-season, finally finding the net in the Blaugrana's 5th and final pre-season game, in a 4-0 rout of Italian giants Napoli.Barcelona's Pre-Season Results: LWWWW23rd June (Saitama, Japan): Barcelona 1-2 Chelsea27th June (Kobe, Japan): Vissel Kobe 0-2 Barcelona04th August (Camp Nou, Barcelona): Barcelona 2-1 Arsenal08th August (Miami, USA): Barcelona 2-1 Napoli11th August (Ann Arbor, USA): Napoli 0-4 BarcelonaRakitic celebrates after scoring against Napoli in Barcelona's pre-season tour of the USAFitting Frenkie de Jong into the Blaugrana starting lineup will be more of a challenge for Valverde with Barcelona boasting some of the best central midfielders on the planet.Sergi Busquets and Ivan Rakitic are nailed down to start and Valverde's decision has been made simpler with the injury absences of Copa America winner Arthur as well as Arturo Vidal.La Masia products Carles Alena and Sergi Roberto will probably make way for the dynamic Dutch midfielder De Jong in Valverde's preferred 3 man midfield. Furthermore, Valverde will be more inclined to select the 22-year-old starlet owing to his superior physicality, which will come in handy against a bruising Bilbao side.Barcelona predicted line-up vs Athletic Bilbao