Here is a full list of summer transfers in 2015. It's getting pretty busy now...
Like an elderly, grumpy cat that has given up its duties as a family pet and now expects to be able to do exactly as it pleases in its twilight years. It's Mark Lawrenson...
It's fair to say that very few sides really set the world alight in the opening round of Premier League fixtures, with Chelsea - the favourites of many this season - arguably making the strongest start.
The man at the centre of the Blues' 3-1 win at Burnley was one that still looks odd in that colour, though in terms of the way that he gelled into the side, Cesc Fabregas certainly didn't look out of place. If anything the former Arsenal fan favourite looked like the most comfortable player on the pitch, and undoubtedly the most accomplished on the night.
His was a competitive debut that heralded two assists, with the first likely to prove a tough through ball to trump by any player all season. It highlighted a guile in the attacking third that Chelsea lacked last season, and it's little surprise that the Spaniard was awarded WhoScored.com's man of the match award with a rating of 8.73.
In an all-round display of the highest quality Fabregas had at least 18 touches of the ball more than any other player at Turf Moor (106), completing 78 passes, creating three chances and producing a joint-high three tackles for the away side. Coupled with the arrival of Diego Costa, who took just 16 minutes to open his account for the club - earning an encouraging rating of 7.60 from WhoScored - the (extremely) early evidence backs up the theory that Mourinho's men should be title favourites.
Fabregas and Costa's weren't the only impressive debuts this weekend, with a number of opening displays proving noteworthy of those to have made summer moves.
Patrick van Aanholt, who left Stamford Bridge in search of regular first-team football at Sunderland, certainly showed glimpses that he could be an astute acquisition on Wearside. The full-back will have been disappointed not to have tracked the back post run of Saido Berahino for West Brom's second goal of the game but it was a rare blip in an otherwise impressive display.
The Dutchman made amends by getting to the byline and pulling back for Seb Larsson to notch the Black Cats' late equaliser and was a constant menace down the flank. The aforementioned Swede was the only player for the visitors to have more touches over the 90 minutes (62), with 43% of Sunderland's attacking touches coming down Van Aanholt's left-hand side. Meanwhile, from a defensive perspective no player made more interceptions on the opening weekend (8), with the 23-year-old also producing five tackles to earn a rating of 8.50 from WhoScored.com.
Elsewhere, it may not have been a debut for Gylfi Sigurdsson at Swansea but it was the Icelander's first appearance as a permanent member of their playing squad having returned to Wales - where he spent half a season on loan in 2012 - after a frustrating spell with Spurs. The 24-year-old had a hand in both goals as Garry Monk's side secured the shock result of the weekend, assisting the first in a flowing Swans move before notching the winner at Old Trafford himself.
Swansea were hoping to sign the playmaker after his period on loan at the club heralded seven goals and three assists and have had to wait to get their man. It was worth it though, as Sigurdsson put in a typically hard-working display, contributing two tackles and three interceptions, and was efficient at the business end, with both of his efforts at goal hitting the target and his one key pass setting up Ki's opener to earn a WhoScored rating of 8.45.
Sigurdsson's former employers Spurs got off to a winning start with an unlikely hero making a name for himself and instantly winning a place in the fans' hearts. Eric Dier has been a Brit abroad for much of his early career but returned to England having spent his formative years with Sporting Lisbon. The 20-year-old was thrown in at the deep end due to injuries at the back in Pochettino's first game in charge, starting in his favoured centre-back position before a first-half Kyle Naughton dismissal forced him to fill in on the right.
The switch didn't faze Dier though, who showed an ability to contribute going forward, not least by rounding Adrian to net the only goal of the game against London rivals West Ham in injury time. The youngster also completed two dribbles and was assured in possession, which will have appeased the new manager, finding his man with 88.6% of his pass attempts to pick up a rating of 7.98 from WhoScored.com.
Across London, in the other capital city derby of the opening day, much was expected of Arsenal's marquee signing Alexis Sanchez. It was a game of mixed fortunes for the Chilean, who showed signs of the energy and spark that we have come to expect but was understandably a little rusty after a limited pre-season campaign.
Sanchez picked up an assist with a well-placed free-kick finding the run of Laurent Koscielny to open the scoring. It was one of five key passes on the day, with only Joey Barton registering more (6) in the first round of fixtures, and though a little wasteful in possession at times, the 25-year-old gave a glimpse of what he can do to whet the home fans' appetite, securing a rating of 7.80.
Martin Laurence - follow him on Twitter
All statistics courtesy of WhoScored.com, where you can find yet more stats, including live in-game data and unique player and team ratings.