The match gets underway at 6pm BST as they look to claim a win over the Liga Portugal 2 side in their first outing since last season.
Following their international trip, the Blades are due to also face Lincoln City, Scunthorpe United, Mansfield Town, Burton Albion and Barnsley, before travelling south for their first Championship clash with Watford next month.
Here are today’s rumours...
1. Millwall reject second bid for defender
Millwall have reportedly turned down a second offer from QPR for young defender Danny McNamara. It is thought the West London club had come back with a bid of around £300k. (Football Insider)
2. Watford closing in on Barcelona striker
Watford are reportedly nearing a deal for Barcelona's Rey Manaj, with the forward expect in London tomorrow. The 25-year-old scored five goals while on loan with Spezia last season. (Fabrizio Romano)
3. League One club target released Lilywhites defender
Portsmouth are thought to be considering a move for Joe Rafferty after he was released by Preston North End last month. Tranmere Rovers are also keen on signing the 28-year-old. (HampshireLive)
4. Swansea City linked with Premier League teenager
Swansea City are among the clubs linked with a loan deal for Brentford defender Fin Stevens. Reading and Blackpool are also thought to be keen. (Blackpool Gazette)