Burnley have had an opening offer of £8 million for Nottingham Forest striker Britt Assombalonga rejected, according to various reports.

Sky Sports, the Daily Mail and The Sun have all reported that the Clarets have made an official bid for the DR Congo striker, one of their main targets as they look prepared to lose star striker Andre Gray.

A proven goalscorer destined for top flight

Assombalonga, who scored 14 goals last season for Forest as they escaped relegation to League One on the final day of the season with a 3-0 win over Ipswich Town, is thought to be valued a lot more highly by the club, with him contracted with the club until 2021.

Forest manager Mark Warburton has already stated that he does not want Assombalonga to leave the club and will only allow a deal to go through if it is in the best interests of the club. It is thought that any bid below around £15 million would not be considered by the club. However, this could change if Assombalonga's head is swayed by a potential Premier League move.

This is unlikely to be the end of negotiations between the two sides with Sean Dyche eager to strike a deal for the forward. This is not the first time Dyche has targeted a Forest player. He attempted to sign Henri Lansbury several times whilst he was at The City Ground before he eventually moved to Aston Villa in January.

Despite having their first offer quickly rebuffed, the Clarets are expected to go back in with a higher offer. Dyche will be hoping that the fact he has previously worked with the 24-year-old at Watford will have an influence on Assombalonga's decision.

The striker has scored goals on a consistent basis throughout his career so far. He found the back of the net 23 times in 43 appearances for Peterborough United in League One which ultimately saw him make the switch to Forest. During his time with the Reds so far, he has scored 30 goals in 65 appearances. However, his time at the club has been marred in recent years by a horrific knee injury which he has only recently fully recovered from.

The start of a long transfer saga?

Forest officials are expecting this bid to be one of many offers made for their main man this summer, but following the takeover by new owner Evangelos Marinakis, it is unlikely that any player will now be allowed to leave The City Ground on the cheap.

Burnley are not the only side interested in securing the services of the striker this summer with recently relegated Middlesbrough also said to be in the hunt. Garry Monk is said to be interested in making the striker one of his main signings this summer as he looks to build a Boro squad capable of challenging for an immediate return to the top flight. However, they are yet to make a concrete bid but may be forced into action by Burnley's movement today.

Considering Forest paid £5.5 million for Assombalonga when he joined from Peterborough United in 2012, the bid of £8 million from Burnley was always likely to be rejected. A fee of around £15 million is likely to be required to get Forest even thinking about doing business.

However, this could all change if Assombalonga decided he wanted to leave for Burnley and test himself in the top flight. This would mean Forest could be more willing to do business if the player became unsettled. Forest supporters will be hopeful that the striker remains loyal to the club after they remained patient with him whilst recovering from his career threatening injury.

Whatever happens in the coming weeks, this is unlikely to be the last time we hear about Assombalonga during this transfer window. Without doubt, Forest have a big job on their hands to fend off interest in their main man ahead of the start of next season.