Southampton continued their summer rebuilding on Thursday with the signings of Shane Long and Florin Gardos.
The Republic of Ireland international only joined the Tigers from West Brom in January but now moves to St. Mary's on a four-year deal.
Gardos also agreed a four-year contract at St. Mary's, Southampton announced on their website, with the centre-back joining for a fee believed to be £6m from Romanian champions Steaua Bucharest.
Long moves for an undisclosed fee after scoring four goals in 15 appearances for Steve Bruce's side last season.
Long will provide some much needed attacking impetus for Southampton boss Ronald Koeman alongside fellow new recruit Graziano Pelle after the departures of striker Rickie Lambert and midfield talisman Adam Lallana.
"Shane is a very good player. As a striker, he's different to Graziano Pelle, which is something we needed," Koeman told the club's official website.
"He brings ambition and a great mentality. He's always running and always working, and he's very down-to-earth. He's a great person, and we need that type of player.
"He brings a lot of experience to our squad because he's already played at Premier League level for a few years. He knows what we need at this level, and he can show that to our younger players as well.
"Shane will be an important player for us and our future."
Long first moved to England with Reading and spent six years at the Madejski Stadium before moving to West Brom in the summer of 2011. He spent two-and-a-half years with the Baggies before his short stint in East Yorkshire and cannot wait to get started with his third club in seven months.
"I'm delighted," he said. "This came out of the blue for me but, once I'd come and had a look at the training facilities and met the manager, it seemed like the right decision for me and my family.
"It was a hard decision for me to make, but when you come down to Southampton you see how big a club it is and how well set up it is.
"You look at how well they did last season and they are developing a new squad for this year to try and achieve those accomplishments again, and hopefully I can be a big part of that.
"Southampton play a brand of football that's enjoyable to watch, and I'm sure it'll be enjoyable to play in as well. I think the formation they play will suit me, and the manager has a lot of knowledge about football and I'm looking to learn off him.
"In theory it's a very good move for me, but all the hard work starts tomorrow when I get on the training pitch because I have to prove my worth."
Gardos comes to the Premier League after winning back-to-back Romanian titles with Steaua and Koeman believes the 25-year-old will only improve as he fills the gap left by Lovren.
"I am very happy to have Florin here," he said. "He's still a young player so he can develop himself a lot more, and that's part of the ambition of Southampton.
"From the beginning, after Lovren left the club, we paid a lot of attention to Florin. Everybody knows the big names and the big players, but it's always more difficult to find one who's not so well known. The information the club has given to me about him has been very good. For now and for the future, we have a very good central defender."
Gardos, a 12-cap Romania international, added: "This is one of the happiest days of my life. It's the biggest step of my career so far.
"Coming to the Premier League is a very big occasion for me, and Southampton was a team that had a really good last season so this wasn't really a hard decision.
"I've had a very good first impression of the club. There's a very big difference between what I had back home and what is here.
"I've always said that coming to Premier League would be a dream come true, and luckily I've been able to achieve that dream now."