The former Celtic marksman, who plans to move back in with his parents, completed the switch yesterday following a medical, but a groin injury and a Europa League signing deadline mean he will not be available for tonight’s visit of Birkirkara.
The 22-year-old is best remembered for scoring the winning Champions League goal against Barcelona for Celtic in November 2012, but he has struggled to realise his full potential since then.
Watt joined Belgian outfit Lierse on loan a year later before signing a permanent deal at Standard Liege.
A switch to Charlton in 2015 followed and Watt spent time on loan at Cardiff and Blackburn Rovers last season.
Questions have been raised over the player’s workrate in the past and Scotland assistant manager Mark McGhee admitted in March he would love to “smack him around” prior to Watt’s international debut against the Czech Republic.
But Watt insists the stability of being back in the family home can help him put all his energy into football.
He said: “I’m still young and I know I’ve got my career in front of me. I want to come back and play games.
“I’ve had a groin injury recently and I’ve been away from my family for a few years.
“Hearts are a big club and I want to come back and get some stability in my life and kick on.
“I had a stop-start season last year due to a few things: injuries, a transfer embargo (at Cardiff). Then I went back to Charlton and it wasn’t for me, and I wanted to be closer to home. “It won’t take me time to settle, I’ll be back with my family, back at my mum and dad’s house.
“I want to play 40 games a season and I want to be back closer to my family, sometimes it’s difficult being away.
“I know people will say, ‘he’s a footballer’, but sometimes it’s difficult being away from home since I was 18, 19 and maybe it’s time for a year or two to come back and settle down and kick on.”A groin complaint brought last season to a premature end for Watt during his time at Rovers but the marksman is targeting a debut in the Europa League third qualifying round against Russian side Krasnodar, providing Robbie Neilson’s side can see off Maltese outfit Birkirkara in this evening’s second leg.
He added: “I did my physio at Hampden over the summer, I missed the last month of the season last year but I should be okay now.
“I just need game time, I took it slowly and watched my rehab. It’s gone fine I think.
“I’m not far away, I would hope to be involved in the first leg and hopefully a big part in the second leg, and hopefully for the first game of the season against Celtic.
“There’s a good squad here but if I do my own thing, I’m sure I can be challenging to start every game and play a big role in the season.
“I know the league inside out, I played here for years and hopefully I can come back and play well and challenge at the right end of the table.”