Southampton have completed the signing of forward Adam Armstrong from Blackburn on a four-year deal for an undisclosed fee.The addition of the prolific striker helps fill the void left by the departure of last seasons top goalscorer Danny Ings to Aston Villa earlier this month. Armstrong scored 28 goals for Blackburn in the Sky Bet Championship during the 2020-21 campaign.Following his Saints arrival, Armstrong said: “Its unbelievable to be here such a massive club with a great fanbase and its just something that Im really looking forward to.“I thought it was perfect as my next step. I wanted to get back to the Premier League from what Ive done for Blackburn, so Im over the moon.”Contract Shirt Tunnel Let’s have your welcome messages for @AdamArma9! pic.twitter.com/9IPlys6q2E Southampton FC (@SouthamptonFC) August 10, 2021The signing follows up the addition of striker Armando Broja on a season-long loan from Chelsea earlier on Tuesday.The 19-year-old signed a five-year contract with the European champions this summer but will spend the entire 2021/22 campaign at St Marys.Boss Ralph Hasenhuttl added: “Armando is a very talented player who we were impressed by last season.“He is young, but he comes now with a full season of experience in senior football with a good team, and he brings a lot of qualities that can help us.”READ MORE: Duos emergence makes axing expensive Liverpool star an easy decision