Celtic manager Brendan Rodgers has been assessing his new squad in training for the first time this week.
The Tottenham Hotspur pair helped their side reach the last 16 of Euro 2016 this week.
The defender was part of Boro's League Cup win over Sunderland four years ago, and is eyeing another successful trip to Wearside.
The Spaniard will be hoping to lead the Magpies back to the Premier League at the first time of asking.
Welcome to this morning's transfer round-up. This edition features 'Manchester United looking at Aaron Ramsey?' and 'Atletico Madrid looking at Cesar Azpilicueta?' plus more, so delve in below.
Rangers target James Vaughan wants to hold talks over his future next week.
The midfielder agreed to join Rangers on a free transfer last month.
Sterling has been heavily criticised by England fans, but could still have a role to play at this summer's European Championship.
Wales international Joe Ledley is reportedly on the Clarets' radar.
United have finished in the bottom half of the Championship table for the past five seasons.
HITC Sport understands several Premier League clubs have already been knocked back in trial requests for the talented winger.
The Brazil international has been heavily linked with the likes of Arsenal, Tottenham Hotspur and Liverpool.
The former England international has questioned the logic by some selection decisions made of late.